1. Structure of algebras;Albert,1939
2. Algèbre;Bourbaki,1958
3. Topologie Générale;Bourbaki,1960
4. The algebraic theory of semigroups;Clifford;(Am. Math. Soc.), Math. Surveys.,1961
5. The structure of nonsemisimple algebras;Curtis;Duke Math. J.,1954