Physics Letters, Section A: General, Atomic and Solid State Physics

Physics Letters, Section A: General, Atomic and Solid State Physics. Vol. 141. 1989. P. 249-250

Physics Letters, Section A: General, Atomic and Solid State Physics. Vol. 132. 1988. P. 85-87

Physics Letters, Section A: General, Atomic and Solid State Physics. Vol. 123. 1987. P. 215-216

Physics Letters, Section A: General, Atomic and Solid State Physics. Vol. 100. 1984. P. 357-359

Physics Letters, Section A: General, Atomic and Solid State Physics. Vol. 91. 1982. P. 95-97

Physics Letters, Section A: General, Atomic and Solid State Physics. Vol. 87. 1982. P. 220-222

Physics Letters, Section A: General, Atomic and Solid State Physics. Vol. 80. 1980. P. 249-252

Physics Letters, Section A: General, Atomic and Solid State Physics. Vol. 55. 1975. P. 149-150

Physics Letters, Section A: General, Atomic and Solid State Physics. Vol. 55. 1975. P. 155-156

Physics Letters, Section A: General, Atomic and Solid State Physics. Vol. 44. 1973. P. 190-192

Physics Letters, Section A: General, Atomic and Solid State Physics. Vol. 39. 1972. P. 368-370

Physics Letters, Section A: General, Atomic and Solid State Physics. Vol. 34. 1971. P. 222-223