PHYSICAL REVIEW B, vol. 51, no. 16, page. 10436 - 10442, 1995-04-15
PHYSICAL REVIEW B, vol. 49, no. 14, page. 9697 - 9701, 1994-04-01
PHYSICAL REVIEW B, vol. 50, no. 6, page. 4030 - 4033, 1994-08-01
SOLID STATE COMMUNICATIONS, vol. 88, no. 8, page. 653 - 657, 1993-11
PHYSICAL REVIEW B, vol. 51, no. 2, page. 1039 - 1044, 1995-01-01
JOURNAL OF PHYSICS-CONDENSED MATTER, vol. 7, no. 19, page. 3789 - 3800, 1995-05-08