1. Meta-ideals;Baer;Report of a conference on linear algebra,1956
2. Algebraic sets in groups and Lie algebras;Plotkin;Uspekhi Mat. Nauk.,1958
3. Two radicals of Lie algebras;Simonjan;Dokl. Akad. Nauk.,1964
4. The Engel elements of a soluble group;Gruenberg;Illinois J. Math.,1959