Kanguzhin, B.E., M.O. Mustafina, and O.A. Kaiyrbek. “Well-Posed Problems for the Laplace-Beltrami Operator on a Stratified Set Consisting of Punctured Circles and Segments”. Bulletin of the Karaganda University. Mathematics Series 119, no. 3 (September 30, 2025): 150–163. Accessed October 5, 2025. https://mts.buketov.edu.kz/index.php/mathematics-vestnik/article/view/994.