Syzdykov, Mirzakhmet. “Membership Problem in Non-Deterministic Finite Automata for Extended Regular Expressions in Linear Polynomial Time”. ADVANCED TECHNOLOGIES AND COMPUTER SCIENCE 1, no. 4 (December 20, 2021): 14–17. Accessed June 7, 2025. https://www.atcs.iict.kz/index.php/atcs/article/view/71.