Zaevski, T., O. Kounchev, D. Palejev, and E. Stoimenova. “SPECTRAL CLUSTERING OF MULTIDIMENSIONAL GENETIC DATA”. Ann. Sofia Univ. Fac. Math. And Inf., vol. 104, Dec. 2017, pp. 201-15, https://stipendii.uni-sofia.bg/index.php/fmi/article/view/46.