1. E. M. Andreev, É. B. Vinberg, and A. G. Élashvili, "Orbits of greatest dimensionality of semisimple Lie groups," Funktsional'. Analiz i Ego Prilozhen.,1, No. 4, 3?7 (1968).
2. É. B. Vinberg and A. L. Onishchik, Seminar on Algebraic Groups and Lie Groups, 1967/68 [in Russian], Mimeographed, VTs Moscow State University, Mekh.-Matem. Fak., Moscow (1969).
3. E. B. Dynkin, "Semisimple subalgebras of semisimple Lie algebras," Matem. Sb.,30, 349?362 (1952).
4. N. Jacobson, Lie Algebras [Russian translation], IL, Moscow (1964).