@article{SEMR_2012_9_a11,
     author = {Ya. A. Kopylov},
     title = {On the homology sequence in a $P$-semi-abelian category},
     journal = {Sibirskie \`elektronnye matemati\v{c}eskie izvesti\^a},
     pages = {190--200},
     publisher = {mathdoc},
     volume = {9},
     year = {2012},
     language = {en},
     url = {http://geodesic.mathdoc.fr/item/SEMR_2012_9_a11/}
}