@article{HHA_2017_19_1_a9,
     author = {Alan S. Cigoli and Sandra Mantovani and Giuseppe Metere},
     title = {Peiffer product and {Peiffer} commutator for internal pre-crossed modules},
     journal = {Homology, homotopy, and applications},
     pages = {181--207},
     publisher = {mathdoc},
     volume = {19},
     number = {1},
     year = {2017},
     doi = {10.4310/HHA.2017.v19.n1.a10},
     language = {en},
     url = {http://geodesic.mathdoc.fr/articles/10.4310/HHA.2017.v19.n1.a10/}
}