Multiple nearest-neighbor exchange model for the frustrated Keplerate magnetic molecules Mo72Fe30 and Mo72C
C. Schröder, R. Prozorov, P. Kögerler, M.D. Vannette, X. Fang, M. Luban, A. Matsuo, K. Kindo, A. Müller, A.M. Todea, Physical Review / The American Physical Society. B, Condensed Matter and Materials Physics 77 (2008) 224409.

Multiple nearest-neighbor exchange model for the frustrated magnetic molecules and
C. Schröder, R. Prozorov, P. Kögerler, M.D. Vannette, X. Fang, M. Luban, A. Matsuo, K. Kindo, A. Müller, A.M. Todea, Physical Review / The American Physical Society. B, Condensed Matter and Materials Physics 77 (2008).

Finite quantum Heisenberg spin models and their approach to the classical limit
L. Engelhardt, M. Luban, C. Schröder, Physical Review B 74 (2006).