1. Butler groups of infinite rank and Axiom 3;Albrecht;Czechoslovak Math. J.,1987
2. Pure subgroups of finite rank completely decomposable groups;Arnold,1981
3. Notes on Butler groups and balanced extensions;Arnold;Boll. Un. Mat. Ital. A,1986
4. Splitting in abelian groups;Bican;Czechoslovak Math. J.,1978
5. Butler groups of infinite rank;Bican,1983