1. The denormalized 3×3 lemma;Bourn;J. Pure Appl. Algebra,2003
2. Commutator theory in strongly protomodular categories;Bourn;Theory Appl. Categ.,2004
3. Centrality and normality in protomodular categories;Bourn;Theory Appl. Categ.,2001
4. Centrality and connectors in Maltsev categories;Bourn;Algebra Universalis,2002
5. Regular, protomodular, and abelian categories;Bourn,2004