Endomorphisms of group-type quasi-automata. - István Babcsányi (Acta Cybern., 1976)

Characteristically free quasi-automata. - István Babcsányi (Acta Cybern., 1977)

Mealy-Automata in Which the Output-Equivalence is a Congruence. - István Babcsányi; A. Nagyr (Acta Cybern., 1994)

Right Group-Type Automata. - István Babcsányi; Attila Nagy (Acta Cybern., 1995)

Equivalence of Mealy and Moore Automata. - István Babcsányi (Acta Cybern., 2000)

Automata with Finite Congruence Lattices. - István Babcsányi (Acta Cybern., 2007)

The Cerny Conjecture for Automata with Blocking States. - István Babcsányi (Automata, Formal Languages, and Related Topics, 2009)