Strict refinement for direct sums and graphs. Iskander, A.A. — 1999 Acta Mathematica Universitatis Comenianae. New Series
Factorable congruences and strict refinement. Iskander, A.A. — 1996 Acta Mathematica Universitatis Comenianae. New Series
Solvability of equations in varieties of universal algebras. Csákány, B.; Iskander, A.A. — 1993 Acta Mathematica Universitatis Comenianae. New Series