1. Exact Categories;Barr,1971
2. Normalization Equivalence, Kernel Equivalence and Affine Categories;Bourn,1991
3. Polyhedral monadicity of n-groupoids and standardized adjunction;Bourn;J. Pure Appl. Algebra,1995
4. Normal subobjects and abelian objects in protomodular categories;Bourn;J. Algebra,2000
5. Normal functors and strong protomodularity;Bourn;Theory Appl. Categories,2000