Complete system of equivalent transformations for two-tape automata with disjoint loops. - Rimma I. Podlovchenko; V. E. Khachatryan; Yu. G. Chashin (Program. Comput. Softw., 2000)

Complete System of Equivalent Transformations for Multitape Automata. - V. E. Khachatryan (Program. Comput. Softw., 2003)

A New Approach to Solving Equivalence Problem. - Rimma I. Podlovchenko; V. E. Khachatryan (Program. Comput. Softw., 2004)

The problem of equivalent transformations for homogeneous multitape automata. - V. E. Khachatryan (Program. Comput. Softw., 2008)