Nikitin Валентин, Baizhumanov Сапархан, Kashagan Бакыт, and Dauletova Жанна. “About Watches and Dials”. Рroblems of engineering and professional education 7, no. 7 (January 25, 2023): 73. Accessed December 6, 2025. https://bulprengpe.enu.kz/index.php/main/article/view/303.