The Mal'tsev operation on extensions
Cahiers de Topologie et Géométrie Différentielle Catégoriques, Tome 49 (2008) no. 3, pp. 176-195.
@article{CTGDC_2008__49_3_176_0,
     author = {Bourn, Dominique},
     title = {The Mal'tsev operation on extensions},
     journal = {Cahiers de Topologie et G\'eom\'etrie Diff\'erentielle Cat\'egoriques},
     pages = {176--195},
     publisher = {Dunod \'editeur, publi\'e avec le concours du CNRS},
     volume = {49},
     number = {3},
     year = {2008},
     zbl = {1166.18002},
     mrnumber = {2449672},
     language = {en},
     url = {http://archive.numdam.org/item/CTGDC_2008__49_3_176_0/}
}
Bourn, Dominique. The Mal'tsev operation on extensions. Cahiers de Topologie et Géométrie Différentielle Catégoriques, Tome 49 (2008) no. 3, pp. 176-195. http://archive.numdam.org/item/CTGDC_2008__49_3_176_0/

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