Кunenets, N.     The technology of hierarchical agglomerative cluster analysis in library research [Текст] / N. Кunenets // Econtechmod : intern. quart. j. on econ. in technology, new technologies a. modelling processes / Pol. Acad. of Sciences, Univ. of Engineering and Econ. in Rzeszow, Lviv Polytechnic Nat. Univ. — Lublin ; Rzeszow : Polish Acad. of Sciences Branch, 2016. — P. 35-41.