1.
Tonkov T. The contribution of Nikola Obreshkoff to the theory of diophantine approximation. Ann. Sofia Univ. Fac. Math. and Inf. [Internet]. 1997 Dec. 12 [cited 2025 Jan. 15];89:47-58. Available from: https://admin.uni-sofia.bg/index.php/fmi/article/view/354