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Investigación

Publicaciones

Bibliografía completa.

Artículos en revistas

  1. A. González-López y L. Martínez Alonso, “Photon position eigstates in configuration space,” Phys. Rev. A 114 (2026) 022204.

  2. M. Zapata, F. Finkel y A. González-López, “Local fermion density in inhomogeneous free-fermion chains: a WKB approach,” SciPost Phys. 20 (2026) 078(36).

  3. F. Finkel y A. González-López, “Thermodynamics and criticaliy of supersymmetric spin chains of Haldane–Shastry type,” Phys. Rev. E 110 (2024) 064118(16).

  4. B. Basu-Mallick, F. Finkel y A. González-López, “A novel translationally invariant supersymmetric chain with inverse-square interactions: partition function, thermodynamics and criticality,” J. Stat. Mech.-Theory E. (2024) 113102(49).

  5. B. Basu-Mallick, F. Finkel, A. González-López y D. Sinha, “Integrable coupled massive Thirring model with field values in a Grassmann algebra,” J. High Energy Phys. 11 (2023) 018(33).

  6. F. Finkel y A. González-López, “Thermodynamics and criticaliy of su( m ) spin chains of Haldane–Shastry type,” Phys. Rev. E 106 (2022) 054120(11).

  7. J. Carrasco, F. Finkel, A. González-López y M.A. Rodríguez, “The open supersymmetric Haldane–Shastry spin chain and its associated motifs,” Adv. Theor. Math. Phys. 26 (2022) 2963-3015.

  8. F. Finkel, A. González-López y M.A. Rodríguez, “The open Haldane–Shastry chain: thermodynamics and criticality,” J. Stat. Mech.-Theory E. (2022) 093102(51).

  9. F. Finkel y A. González-López, “Entanglement entropy of inhomogeneous XX spin chains with algebraic interactions,” J. High Energy Phys. (2021) 184(35).

  10. F. Finkel y A. González-López, “Inhomogeneous XX spin chains and quasi-exactly solvable models,” J. Stat. Mech.-Theory E. (2020) 093105(41).

  11. B. Basu-Mallick, F. Finkel y A. González-López, “A novel class of translationally invariant spin chains with long-range interactions,” J. High. Energy Phys. (2020) 099(43).

  12. B. Basu-Mallick, N. Bondyopadhaya, J.A. Carrasco, F. Finkel y A. González-López, “Supersymmetric t - J models with long-range interactions: thermodynamics and criticality,” J. Stat. Mech.-Theory E. (2019) 073104(43).

  13. B. Basu-Mallick, N. Bondyopadhaya, J.A. Carrasco, F. Finkel y A. González-López, “Supersymmetric t - J models with long-range interactions: partition function and spectrum,” J. Stat. Mech.-Theory E. (2019) 043105(27).

  14. F. Finkel, A. González-López, I. León y M.A. Rodríguez, “Thermodynamics and criticality of supersymmetric spin chains with long-range interactions,” J. Stat. Mech.-Theory E., (2018) 043101(47).

  15. M. Baradaran, J.A. Carrasco, F. Finkel y A. González-López, “Jastrow-like ground states for quantum many-body potentials with near-neighbors interactions,” Ann. Phys.-New York 388 (2018) 147–161.

  16. J.A. Carrasco, F. Finkel y A. González-López, “Generalized Lipkin–Meshkov–Glick models of Haldane–Shastry type,” J. Stat. Mech.-Theory E. (2017) 103102(25).

  17. J.A. Carrasco, F. Finkel, A. González-López y P. Tempesta, “A duality principle for the multi-block entanglement entropy of free fermion systems,” Sci. Rep.-UK 7 (2017) 11206(11).

  18. J.A. Carrasco, F. Finkel, A. González-López, M.A. Rodríguez y P. Tempesta, “Supersymmetric spin chains with nonmonotonic dispersion relation: Criticality and entanglement entropy,” Phys. Rev. E 95 (2017) 012129(15).

  19. J.A. Carrasco, F. Finkel, A. González-López, M.A. Rodríguez y P. Tempesta, “Critical behavior of su(1|1) supersymmetric spin chains with long-range interactions,” Phys. Rev. E 93 (2016) 062103(12).

  20. B. Basu-Mallick, F. Finkel y A. González-López, “Integrable open spin chains related to infinite matrix product states,” Phys. Rev. B 93 (2016) 155154(10).

  21. J.A. Carrasco, F. Finkel, A. González-López, M.A. Rodríguez y P. Tempesta, “Generalized Lipkin–Meshkov–Glick models: ground state entanglement and quantum entropies,” J. Stat. Mech.-Theory E. (2016) 033114(33).

  22. F. Finkel y A. González-López, “Yangian-invariant spin models and Fibonacci numbers,” Ann. Phys.-New York 361 (2015) 520–547.

  23. B. Basu-Mallick, C. Datta, F. Finkel y A. González-López, “Rational quantum integrable systems of D N type with polarized spin reversal operators,” Nucl. Phys. B 898 (2015) 53–77.

  24. F. Finkel y A. González-López, “Exact solution and thermodynamics of a spin chain with long-range elliptic interactions,” J. Stat. Mech.-Theory E. (2014) P12014(28).

  25. F. Finkel y A. González-López, “A new perspective on the integrability of Inozemtsev's elliptic spin chain,” Ann. Phys.-New York 351 (2014) 797–827.

  26. B. Basu-Mallick, F. Finkel y A. González-López, “The exactly solvable spin Sutherland model of B N type and its related spin chain,” Nucl. Phys. B 866 (2013) 391–413.

  27. A. Enciso, F. Finkel y A. González-López, “Thermodynamics of spin chains of Haldane–Shastry type and one-dimensional vertex models,” Ann. Phys.-New York 37 (2012) 2627–2665.

  28. B. Basu-Mallick, F. Finkel y A. González-López, “The spin Sutherland model of D N type and its associated spin chain,” Nucl. Phys. B 843 (2011) 505–533.

  29. A. Enciso, F. Finkel y A. González-López, “Level density of spin chains of Haldane–Shastry type,” Phys. Rev. E 82 (2010) 051117(6).

  30. J.C. Barba, F. Finkel, A. González-López y M.A. Rodríguez, “Inozemtsev’s hyperbolic spin model and its related spin chain,” Nucl. Phys. B 839 (2010) 499–525.

  31. J.C. Barba, F. Finkel, A. González-López y M.A. Rodríguez, “1/ f a noise and integrable systems,” Phys. Rev. E 80 (2009) 047201(4).

  32. A. Enciso, F. Finkel y A. González-López, “Spin chains of Haldane–Shastry type and a generalized central limit theorem,” Phys. Rev. E 79 (2009) 060105(R)-4.

  33. B. Basu-Mallick, F. Finkel y A. González-López, “Exactly solvable D N -type quantum spin models with long-range interaction,” Nucl. Phys. B 812 (2009) 402–423.

  34. J.C. Barba, F. Finkel, A. González-López y M.A. Rodríguez, “An exactly solvable supersymmetric spin chain of BC N type,” Nucl. Phys. B 806 (2009) 684–714.

  35. A. Enciso, F. Finkel, A. González-López y M.A. Rodríguez, “Partially solvable spin chains and QES spin models,” J. Nonlinear Math. Phys. 15 (2008) 155–165.

  36. J.C. Barba, F. Finkel, A. González-López y M.A. Rodríguez, “The Berry–Tabor conjecture for spin chains of Haldane–Shastry type,” Europhys. Lett. 83 (2008) 27005(6).

  37. J.C. Barba, F. Finkel, A. González-López y M.A. Rodríguez, “Polychronakos–Frahm spin chain of BC N type and the Berry–Tabor conjecture,” Phys. Rev. B 77 (2008) 214422(10).

  38. A. Enciso, F. Finkel, A. González-López y M.A. Rodríguez, “A novel quasi-exactly solvable spin chain with nearest-neighbors interactions” Nucl. Phys. B 789 (2008) 452–482.

  39. A. Enciso, F. Finkel, A. González-López y M.A. Rodríguez, “Exchange operator formalism for N -body spin models with near-neighbours interactions,” J. Phys. A 40 (2007) 1857–1883.

  40. A. Enciso, F. Finkel, A. González-López y M.A. Rodríguez, “Quasi-exactly solvable N -body spin Hamiltonians with short-range interaction,” SIGMA 2 (2006) 73(11).

  41. A. González-López y T. Tanaka, “Nonlinear pseudo-symmetry in the framework of N -fold supersymmetry,” J. Phys. A: Math. Gen. 39 (2006) 3715–3723.

  42. F. Finkel y A. González-López, “Global properties of the spectrum of the Haldane–Shastry spin chain,” Phys. Rev. B 72 (2005) 174411(6).

  43. A. González-López y T. Tanaka, “A novel multi-parameter family of quantum systems with partially broken N -fold supersymmetry,” J. Phys. A: Math. Gen. 38 (2005) 5133–5157.

  44. A. Enciso, F. Finkel, A. González-López y M.A. Rodríguez, “A Haldane–Shastry spin chain of BC N type in a constant magnetic field,” J. Nonlinear Math. Phys. 12 (1) (2005) 253–265.

  45. A. Enciso, F. Finkel, A. González-López y M.A. Rodríguez, “Haldane–Shastry spin chains of BC N type,” Nucl. Phys. B 707 (2005) 553–576.

  46. A. Enciso, F. Finkel, A. González-López y M.A. Rodríguez, “Solvable scalar and spin models with near-neighbors interactions,” Phys. Lett. B 605 (2005) 214–222.

  47. A. González-López y T. Tanaka, “A new family of N -fold supersymmetry: type B,” Phys. Lett. B 586 (2004) 117–124.

  48. F. Finkel, D. Gómez-Ullate, A. González-López, M.A. Rodríguez y R. Zhdanov, “On the Sutherland spin model of B N type and its associated spin chain,” Commun. Math. Phys. 233 (2003) 191–233.

  49. G. Álvarez, F. Finkel, A. González-López y M.A. Rodríguez, “Quasi-exactly solvable models in nonlinear optics,” J. Phys. A: Math. Gen. 35 (2002) 8705–8713.

  50. F. Finkel, D. Gómez-Ullate, A. González-López, M.A. Rodríguez y R. Zhdanov, “New spin Calogero–Sutherland models related to B N -type Dunkl operators,” Nucl. Phys. B 613 (2001) 472–496.

  51. F. Finkel, D. Gómez-Ullate, A. González-López, M.A. Rodríguez y R. Zhdanov, “A N -type Dunkl operators and new spin Calogero–Sutherland models,” Commun. Math. Phys. 221 (2001) 477–497.

  52. D. Gómez-Ullate, A. González-López y M.A. Rodríguez, “Quasi-exactly solvable generalizations of Calogero-Sutherland models,” Theor. Math. Phys . 127 (2001) 719–728.

  53. D. Gómez-Ullate, A. González-López y M.A. Rodríguez, “Exact solutions of an elliptic Calogero-Sutherland model,” Phys. Lett. B 511 (2001) 112–118.

  54. F. Finkel, A. González-López, A. L. Maroto y M.A. Rodríguez, “The Lamé equation in parametric resonance after inflation,” Phys. Rev. D 62 (2000) 103515(7).

  55. D. Gómez-Ullate, A. González-López y M.A. Rodríguez, “New algebraic quantum many-body problems,” J. Phys. A: Math. Gen.: Math. Gen. 33 (2000) 7305–7335.

  56. F. Finkel, A. González-López y M.A. Rodríguez, “A new algebraization of the Lamé equation,” J. Phys. A: Math. Gen.: Math. Gen. 33 (2000) 1519–1542.

  57. F. Finkel, A. González-López y M.A. Rodríguez, “On the families of orthogonal polynomials associated to the Razavy potential,” J. Phys. A: Math. Gen. 40 (1999) 3268–3274.

  58. F. Finkel, A. González-López, Niky Kamran y M.A. Rodríguez, “On form-preserving transformations for the time-dependent Schrödinger equation,” J. Math. Phys. 40 (1999) 3268–3274.

  59. A. González-López y Niky Kamran, “The multidimensional Darboux transformation,” J. Geom. Phys. 26 (1998) 202–226.

  60. A. González-López, G. Marí Beffa y R. Hernández Heredero, “Invariant differential equations and the Adler–Gel'fand–Dikii bracket,” J. Math. Phys. 38 (1997) 5711–5719.

  61. F. Finkel, A. González-López y M.A. Rodríguez, “Quasi-exactly solvable Lie superalgebras of differential operators,” J. Phys. A: Math. Gen. 30 (1997) 6879–6892.

  62. F. Finkel, A. González-López y M.A. Rodríguez, “Quasi-exactly solvable spin 1/2 Schrödinger operators,” J. Math. Phys. 38 (1997) 2795–2811.

  63. F. Finkel, A. González-López y M.A. Rodríguez, “Quasi-exactly solvable potentials and orthogonal polynomials,” J. Math. Phys. 37 (1996) 3954–3972.

  64. A. González-López, Niky Kamran y Peter J. Olver, “Real Lie algebras of differential operators and quasi-exactly solvable potentials,” Philos. Trans. R. Soc. Lond. A354 (1996) 1165–1193.

  65. A. González-López, Niky Kamran y Peter J. Olver, “New quasi-exactly solvable Hamiltonians in two dimensions,” Commun. Math. Phys. 159 (1994) 503–537.

  66. A. González-López, Niky Kamran y Peter J. Olver, “Quasi-exact solvability,” Contemporary Math. 160 (1994) 113–140.

  67. A. González-López, “Symmetry bounds of variational problems,” J. Phys. A: Math. Gen. 27 (1994) 1205–1232.

  68. A. González-López, J. Hurtubise, Niky Kamran y Peter J. Olver, “Quantification de la cohomologie des algèbres de Lie de champs de vecteurs et fibrés en droites sur des surfaces complexes compactes,” Comptes Rendus Acad. Sci. (Paris) 136 (1) (1993), 1307–1312.

  69. A. González-López, Niky Kamran y Peter J. Olver, “Normalizability of one-dimensional quasi-exactly solvable Schrödinger operators,” Commun. Math. Phys. 153 (1993) 117–146.

  70. F. G. Gascón y A. González-López, “An algebraic method for problems concerning Lie groups and differential equations,” Hadronic J. 15 (1992) 51–60.

  71. A. González-López, Niky Kamran y Peter J. Olver, “Lie algebras of differential operators in two complex variables,” Am. J. Math. 114 (1992) 1163–1185.

  72. A. González-López, Niky Kamran y Peter J. Olver, “Lie algebras of vector fields in the real plane,” Proc. London Math. Soc. 64 (1992) 339–368.

  73. A. González-López, Niky Kamran y Peter J. Olver, “Quasi-exactly solvable Lie algebras of differential operators in two complex variables,” J. Phys. A: Math. Gen. 24 (1991) 3995–4008.

  74. A. González-López, “On the linearization of second-order ordinary differential equations,” Lett. Math. Phys. 17 (1989) 341–349.

  75. A. González-López, “Symmetry and integrability by quadratures of ordinary differential equations,” Phys. Lett. A133 (1988) 190–194.

  76. A. González-López, “Symmetries of linear systems of second-order ordinary differential equations,” J. Math. Phys. 29 (1988) 1097–1105.

  77. Antonio F. Costa, F. González Gascón y A. González López, “On codimension one submersions of Euclidean spaces,” Invent. Math. 93 (1988) 545–555.

  78. F. González Gascón y A. González-López, “Note on a paper by Anderson,” Gen. Relativ. Gravit. 20 (1988) 951–956.

  79. F. González Gascón y A. González-López, “Note on a paper of Abarbanel and Rouhi concerning Hamiltonian structures for smooth vector fields,” Phys. Lett. A133 (1988) 29–30.

  80. F. González Gascón y A. González-López, “On the possibility of obtaining any first integral of a Hamiltonian system via the Poisson theorem,” J. Phys. A: Math. Gen. 21 (1988) L621–L623.

  81. F. González Gascón y A. González-López, “Newtonian systems of differential equations, integrable via quadratures, with trivial group of point symmetries,” Phys. Lett. A129 (1988) 153–156.

  82. F. González Gascón y A. González-López, “The inverse problem concerning symmetries of ordinary differential equations,” J. Math. Phys. 29 (1988) 618–621.

  83. F. González Gascón y A. González-López, “Note on the impossibility of attaining the speed of light in a finite time,” Hadronic J. 10 (1987) 339–340.

  84. Ph. de Smedt y A. González-López, “On the asymptotic behavior of the solutions of the Caldirola-Kanai equation,” Lett. Math. Phys. 12 (1986) 291–300.

  85. F. González Gascón y A. González-López, “New results concerning systems of differential equations and their symmetry vectors,” Phys. Lett. A7 (1985) 319–321.

  86. F. González Gascón, A. González-López y P. Pascual Broncano, “On Szebehely's equation and its connection with Dainelli-Whittaker's equations,” Celestial Mech. 33 (1984) 85–97.

  87. F. González Gascón y A. González-López, “Some physical results underlying a geometric theorem of Palais,” Hadronic J. 7 (1984) 1546–1583.

  88. F. González Gascón y A. González-López, “Another method for the obtention of first integrals of dynamical systems,” Lett. N. Cimento 39 (1984) 315–318.

  89. F. González Gascón y A. González-López, “The inverse problem concerning the Poincaré symmetry for second-order differential equations,” Hadronic J. 6 (1983) 841–852.

  90. F. González Gascón y A. González-López, “Symmetries of systems of differential equations IV,” J. Math. Phys. 24 (1983) 2006–2021.

  91. F. González Gascón y A. González-López, “On the symmetries of systems of differential equations,” Lett. N. Cimento 32 (1981) 353–360.

Capítulos de libros

  1. F. Finkel, D. Gómez-Ullate, A. González-López, M.A. Rodríguez y R. Zhdanov, “Quasi-exactly solvable N-body problems of Calogero–Sutherland type,” pp. 157–189 in New trends in integrability and partial solvability (NATO Science Series II/132), A.B. Shabat et al., eds., Kluwer, Dordrecht, 2004.

  2. D. Gómez-Ullate, A. González-López y M.A. Rodríguez, “Partially solvable problems in Quantum Mechanics,” pp. 211–231 in Recent Advances in Lie Theory, Research and Exposition in Mathematics, vol. 25, I. Bajo y E. Sanmartín, eds., Heldermann Verlag, Berlin, 2002.

  3. A. González-López, Niky Kamran y Peter J. Olver, “Lie-algebraic Hamiltonians and quasi-exact solvability,” pp. 432–452 in Quasi-Exactly Solvable Models in Quantum Mechanics, by Alexander G. Ushveridze, Institute of Physics Publishing, Bristol, U.K., 1994.

Actas de congresos

  1. F. Finkel, A. González-López y M. A. Rodríguez, “Spin chains of Haldane–Shastry type: a bird’s eye view,” in Quantum Theory and Symmetries. Proceedings of the 11th International Symposium, M.B. Paranjape et al., eds., CRM Series in Mathematical Physics, Springer Nature (2021) 3–20.

  2. F. Finkel, A. González-López, I. León y M. A. Rodríguez, “On the thermodynamics of supersymmetric Haldane--Shastry spin chains,” in 60 years Alberto Ibort Fest. Classical and Quantum Physics: Geometry, Dynamics and Control, G. Marmo et al., eds, Springer Proceedings in Physics, vol. 229, Springer Nature (2019) 187–201.

  3. F. Finkel, D. Gómez-Ullate, A. González-López, Miguel. Á. Rodríguez y R. Zhdanov, “A survey of quasi-exactly solvable models in many-body problems,” in Superintegrability in Classical and Quantum Systems, P. Tempesta et al., eds, CRM Proceedings and Lecture Notes, 37 (2004) 173–186.

  4. G. Álvarez, F. Finkel, A. González-López y Miguel. Á. Rodríguez, “Quasi-exactly solvable models in quantum optics,” in Symmetries in Physics: in Memory of Robert T. Sharp, P. Winternitz et al., eds., CRM Proceedings and Lecture Notes, 34 (2004) 165–176.

  5. D. Gómez-Ullate, F. Finkel, A. González-López, Miguel. Á. Rodríguez y R. Zhdanov, “Quasi-exact solvability and Calogero–Sutherland models,” in Symmetry and Perturbation Theory, S. Abenda et al., eds, World Scientific, Singapore, 2003, pp. 98–105.

  6. F. Finkel, D. Gómez-Ullate, A. González-López, Miguel. Á. Rodríguez y R. Zhdanov, “Quasi-exactly solvable N -body problems of Calogero–Sutherland type,” Actas del X Encuentro de Otoño de Geometría y Física, A. González-López et al., eds., Publicaciones de la RSME, Madrid, 2003, pp. 127–142.

  7. F. Finkel, A. González-López, N. Kamran y M.A. Rodríguez, “On the Darboux transformation for the Schrödinger equation,” Actas del VIII Encuentro de Otoño de Geometría y Física, M. del Olmo y M. Santander, eds., Publicaciones de la RSME, Madrid, 2001, pp. 67–75.

  8. F. Finkel, A. González-López y Miguel. Á. Rodríguez; “Periodic quasi-exactly solvable potentials,” Actas del VIII Encuentro de Otoño de Geometría y Física, M. del Olmo y M. Santander, eds., Publicaciones de la RSME, Madrid, 2001, pp. 77–92.

  9. F. Finkel, A. González-López, A. L. Maroto y M.A. Rodríguez, “Some exact results in preheating from the Lamé equation,” Conference on Cosmology and Particle Physics, (CAPP 2000), R. Durrer, J. García-Bellido y M. Shaposhnikov, eds., AIP, 2001, pp. 293–296.

  10. M.A. Rodríguez, F. Finkel y A. González-López, “Quasi-exactly solvable systems: the Razavy potential,” First International Workshop on Symmetries in Quantum Mechanics and Quantum Optics, A. Ballesteros, F. J. Herranz, J. Negro, L. M. Nieto y C. M. Pereña, eds., Universidad de Burgos, 1999, pp. 271–283.

  11. F. Finkel, A. González-López y M.A. Rodríguez, “Lie superalgebras of differential operators and quasi-exactly solvable systems,” V Wigner Symposium, P. Kasperkovitz y D. Grau, eds., World Scientific, Singapore, 1998, pp. 257–259.

  12. F. Finkel, A. González-López y M.A. Rodríguez, “Quasi-exactly solvable potentials on the line and weakly orthogonal polynomials,” XXI International Conference on Group Theoretical Methods in Physics, H.-D. Doebner, P. Nattermann y W. Scherer, eds., World Scientific, Singapore, 1997, pp. 471–475.

  13. A. González-López y N. Kamran, “The multidimensional Darboux transformation,” XXI International Conference on Group Theoretical Methods in Physics, H.-D. Doebner, P. Nattermann y W. Scherer, eds., World Scientific, Singapore, 1997, pp. 476–480.

  14. A. González López, N. Kamran y P.J. Olver, “Quasi-exact solvability in the real domain,” Field Theory, Integrable Systems and Symmetries, F. Khanna y L. Vinet, eds., Les Publications CRM, Univ. de Montréal, Canada, 1997, pp. 58–70.

  15. F. Finkel, A. González-López y M.A. Rodríguez, “Orthogonal polynomials and quasi-exactly solvable potentials on the line,” International Workshop on Orthogonal Polynomials in Mathematical Physics ; M. Alfaro et al, eds., U. Carlos III (Madrid), 1997, pp. 73–80.

  16. F. Finkel, A. González-López, Niky Kamran, Peter J. Olver y M.A. Rodríguez, “Lie algebras of differential operators and partial integrability,” IV Workshop de Otoño de Geometría Diferencial y sus Aplicaciones, Santiago de Compostela, Spain, 1995.

  17. A. González-López, Niky Kamran y Peter J. Olver, “Quasi-exactly solvable Hamiltonians on two-dimensional manifolds,” XIX International Colloquium on Group Theoretical Methods in Physics, M. A. del Olmo, M. Santander y J. Mateos Guilarte, eds., Anales de Física (Monografías) 1, 1992, vol. I, pp. 233–236.

  18. A. González-López, Niky Kamran y Peter J. Olver, “Lie algebras of first order differential operators in two complex variables,” Canadian Mathematical Society Conference on Differential Geometry, Global Analysis and Topology, A. Nicas y W. F. Shadwick, eds., Canadian Math. Soc. Conference Proceedings, vol. 12, AMS, Providence, R.I., 1991, pp. 51–84.

  19. A. González-López, “Symmetries of linear Newtonian systems,” XV International Colloquium on Group Theoretical Methods in Physics, R. Gilmore, ed., World Scientific, Singapore, 1987, pp. 380–385.

  20. F. González Gascón y A. González López, “Dynamical symmetries and integration of differential equations,” Synergetics, Order and Chaos, M. G. Velarde, ed., World Scientific, Singapore, 1987, pp. 651–654.

  21. F. González Gascón, A. González López y P. Pascual Broncano, “On Szebehely's equation,” Proceedings de las X Jornadas Hispano-Lusas de Matemáticas. IX, Univ. de Murcia, Spain, 1985, pp. 1–2.