Khadzhiivanov, Nikolay, and Nedyalko Nenov. “BALANCED VERTEX SETS IN GRAPHS”. Ann. Sofia Univ. Fac. Math. and Inf. 97 (December 12, 2005): 81–95. Accessed November 24, 2024. https://ftl5.uni-sofia.bg./index.php/fmi/article/view/145.