Yeshkeyev, A.R. “Method of the Rheostat for Studying Properties of Fragments of Theoretical Sets”. Bulletin of the Karaganda University. Mathematics Series 100, no. 4 (December 30, 2020): 152–159. Accessed March 10, 2026. https://mts.buketov.edu.kz/mathematics-vestnik/article/view/397.