1. Minimal identities for algebras;Amitsur,1950
2. On the laws of a metabelian variety;Cohen;J. Alg.,1967
3. Universal Algebra;Cohn,1965
4. Laws in nilpotent-by-finite groups;Cossey,1968
5. T-ideals with the element [[x1, x2], x3[x4, x5]] (Russian);Gavrilov;C. R. Acad. Bulgare Sci.,1968