Kulpeshov, B. and Sudoplatov, S. (2016) “On behaviour of 2-formulas in ordered theories with non-maximal number of countable models”, Bulletin of the Karaganda University. Mathematics Series, 81(1), pp. 68–75. Available at: https://mts.buketov.edu.kz/index.php/mathematics-vestnik/article/view/80 (Accessed: 10 July 2025).