Fiserova, Svetla, and Martin Hrinko. “Study of Acoustic Parameters of Audible and Visual Warning Devices Used by the Police of the Czech Republic”. Communications - Scientific letters of the University of Zilina 14, no. 1 (March 31, 2012): 83-88. Accessed April 6, 2026. http://journals.uniza.sk/index.php/communications/article/view/735.