Safonov K. V., Egorushkin O.I., Kolbasina I.V. «Geometric condition of formal grammars solvability» // Applied Discrete Mathematics. Supplement 2020. №13 C.106-108
Safonov K. V., Egorushkin O.I., Kolbasina I. V. «An analogue of implicit mapping theorem to formal grammars» // Applied Discrete Mathematics. Supplement 2017. №10 C.149-151
Safonov K. V., Kolbasina I. V. «A solvability condition for arbitrary formal grammars» // Applied Discrete Mathematics. Supplement 2019. №12 C.196-198
