@article{GDZPPN002185822, title = {On the homology theory of categories. I.}, journal = {Journal f\"ur die reine und angewandte Mathematik}, volume = {247}, year = {1971}, pages = {133-146}, zbl = {0288.18009}, url = {http://dml.mathdoc.fr/item/GDZPPN002185822} }
Hanna, Azmi. On the homology theory of categories. I.. Journal für die reine und angewandte Mathematik, Tome 247 (1971) pp. 133-146. http://gdmltest.u-ga.fr/item/GDZPPN002185822/