@article{TAC_2016_31_a18,
     author = {Enrico M. Vitale},
     title = {The snail lemma},
     journal = {Theory and applications of categories},
     pages = {484--501},
     publisher = {mathdoc},
     volume = {31},
     year = {2016},
     language = {en},
     url = {http://geodesic.mathdoc.fr/item/TAC_2016_31_a18/}
}