2 joint papers of Alexander Soifer with Shelah

ShSf:239
Shelah+Soifer, Countable $\aleph_ 0$-indecomposable mixed abelian groups of finite torsion-free rank -- J Algebra 100 (1986) 421-429
ShSf:235
Shelah+Soifer, Two problems on $\aleph_ 0$-indecomposable abelian groups -- J Algebra 99 (1986) 359-369