Vardanyan, Seyran M. “On the Powers of Dead-End Recognizing Systems in the Class of T Wo-Element Sets Concerning Operations of Ntersection and Complement”. Mathematical Problems of Computer Science 35 (December 10, 2021): 104–108. Accessed September 28, 2024. http://93.187.165.2/index.php/mpcs/article/view/292.