@article{1183741834,
author = {Sageev, G. and Shelah, S.},
title = {On the Structure of $\operatorname{Ext}(A, \mathbf{Z})$ in ZFC$^+$},
journal = {J. Symbolic Logic},
volume = {50},
number = {1},
year = {1985},
pages = { 302-315},
language = {en},
url = {http://dml.mathdoc.fr/item/1183741834}
}
Sageev, G.; Shelah, S. On the Structure of $\operatorname{Ext}(A, \mathbf{Z})$ in ZFC$^+$. J. Symbolic Logic, Tome 50 (1985) no. 1, pp. 302-315. http://gdmltest.u-ga.fr/item/1183741834/