1. Exact categories;Barr,1971
2. Exact Categories and Categories of Sheaves;Barr,1971
3. Mal'cev, Protomodular, Homological and Semi-Abelian Categories;Borceux,2004
4. Topological semi-Abelian algebras;Borceux;Adv. Math.,2005
5. On the representability of actions in a semi-Abelian category;Borceux;Theory Appl. Categ.,2005