Janacek, Jaroslav, and Ludmila Janosikova. “Higher Territorial Units and Transportation Accessibility of Their Centers”. Communications - Scientific letters of the University of Zilina 4, no. 1-2 (June 30, 2002): 66-72. Accessed April 6, 2026. http://journals.uniza.sk/index.php/communications/article/view/1391.