Naidenova, M., Milev, N. and Kostadinov, G. (2009) “A classification of the uniform coverings”, Ann. Sofia Univ. Fac. Math. and Inf, 99, pp. 121–127. Available at: https://stipendii.uni-sofia.bg/index.php/fmi/article/view/116 (Accessed: 4 December 2024).