@article{JRAM_1977__292_151877,
     author = {Wolfgang Zimmermann},
     title = {...-projektive {Moduln.}},
     journal = {Journal f\"ur die reine und angewandte Mathematik},
     pages = {117--124},
     publisher = {mathdoc},
     volume = {292},
     year = {1977},
     zbl = {0347.16016},
     url = {http://geodesic.mathdoc.fr/item/JRAM_1977__292_151877/}
}