@article{00918296,
title = {Computing crossed modules induced by an inclusion of a normal subgroup, with applications to homotopy 2-types.},
journal = {Theory and Applications of Categories [electronic only]},
volume = {2},
year = {1996},
pages = {3-16},
zbl = {0856.18011},
language = {en},
url = {http://dml.mathdoc.fr/item/00918296}
}
Brown, Ronald; Wensley, Christopher D. Computing crossed modules induced by an inclusion of a normal subgroup, with applications to homotopy 2-types.. Theory and Applications of Categories [electronic only], Tome 2 (1996) pp. 3-16. http://gdmltest.u-ga.fr/item/00918296/