@article{AL_2007_46_3_a5,
     author = {S. Shelah and L. Str\"ungmann},
     title = {The $p$-rank of $\operatorname{Ext}_\mathbb Z(G,\mathbb Z)$ in certain models of~$ZFC$},
     journal = {Algebra i logika},
     pages = {369--397},
     publisher = {mathdoc},
     volume = {46},
     number = {3},
     year = {2007},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/AL_2007_46_3_a5/}
}