@article{GDZPPN002485931,
title = {Surfaces and the Second Homology of a Group.},
journal = {Monatshefte f\"ur Mathematik},
volume = {104},
year = {1987},
pages = {247-254},
url = {http://dml.mathdoc.fr/item/GDZPPN002485931}
}
Zimmermann, Bruno. Surfaces and the Second Homology of a Group.. Monatshefte für Mathematik, Tome 104 (1987) pp. 247-254. http://gdmltest.u-ga.fr/item/GDZPPN002485931/