@article{GDZPPN002198207,
title = {A geometric invariant for modules over an Abelian group.},
journal = {Journal f\"ur die reine und angewandte Mathematik},
volume = {329},
year = {1981},
pages = {170-189},
zbl = {0448.20010},
url = {http://dml.mathdoc.fr/item/GDZPPN002198207}
}
Bieri, Robert; Strebel, Ralph. A geometric invariant for modules over an Abelian group.. Journal für die reine und angewandte Mathematik, Tome 329 (1981) pp. 170-189. http://gdmltest.u-ga.fr/item/GDZPPN002198207/