1. Algebraic Homotopy;Baues,1987
2. The homotopy types of 4-dimensional CW-complexes;Baues,1987
3. Lie groups and Lie algebras;Bourbaki,1972
4. Identities among relations;Brown,1982
5. Modules croisés généralisés de longueur 2;Conduché;J. Pure Appl. Algebra,1984