@article{COMIM_1999__7_1_a2,
     author = {Kehrein, Achim},
     title = {Projective objects in the category of chain complexes},
     journal = {Communications in Mathematics},
     pages = {33--38},
     publisher = {mathdoc},
     volume = {07},
     number = {1},
     year = {1999},
     mrnumber = {1724077},
     zbl = {1022.18008},
     language = {en},
     url = {http://geodesic.mathdoc.fr/item/COMIM_1999__7_1_a2/}
}