1. D. Arnold, R. Hunter andF. Richman, Global Azumaya theorems in additive categories, J. Pure Appl. Algebra16 (1980), 223–242
2. D. Arnold and C. Vinsonhaler, Quasi-isomorphism invariants for a class of torsion-free abelian groups, Houston J. Math. (to appear)
3. D. Arnold and C. Vinsonhaler, Isomorphism invariants for abelian groups, Trans. Amer. Math. Soc. (to appear)
4. L. Fuchs, Infinite Abelian Groups, Vol. II, Academic Press, London-New York, 1973
5. P. Hill and C. Megibben, The classification of certain Butler groups (to appear)