The characteristic elements of special nilpotent Lie algebras of dimension ten. Christophoridou, Ch.; Kobotis, A. — 1999 Balkan Journal of Geometry and its Applications (BJGA)
Determination of invariant inner product on seven dimensional nilpotent Lie algebras. Tsagas, Gr.; Christophoridou, Ch.; Synefaki, A. — 1999 Balkan Journal of Geometry and its Applications (BJGA)