1. The complement of a finitely generated direct summand of an abelian group;Cohn,1956
2. Direct decompositions with finite dimensional factors;Crawley;Pacific J. Math.,1962
3. Refinements for infinite direct decompositions of algebraic systems;Crawley;Pacific J. Math.,1964
4. Abelian Groups;Fuchs,1958
5. Direct Decompositions of Finite Algebraic Systems;Jónsson;Notre Dame Mathematical Lectures, no. 5,1947