Holub, Jan, and Pavel Soucek. “Subjective Testing and Objective Modelling of Influence of Different Social Classes to Voice Call Quality Perception”. Communications - Scientific letters of the University of Zilina 14, no. 2 (June 30, 2012): 17-21. Accessed April 6, 2026. http://journals.uniza.sk/index.php/communications/article/view/741.