PHYSICAL REVIEW B, vol. 46, no. 24, page. 15689 - 15696, 1992-12-15
PHYSICAL REVIEW B, vol. 52, no. 6, page. 4360 - 4365, 1995-08-01
JOURNAL OF MAGNETISM AND MAGNETIC MATERIALS, vol. 126, no. 1-3, page. 316 - 319, 1993-09
JOURNAL OF PHYSICS-CONDENSED MATTER, vol. 5, no. 37, page. 6911 - 6924, 1993-09-13