Gerlici, Juraj, Tomas Lack, and Marta Kadorova. 2004. “Calculation of the Equivalent Conicity Function of the Railway Wheelset Tread Profile at the Delta R Function With a Negative”. Communications - Scientific Letters of the University of Zilina 6 (2), 49-56. http://journals.uniza.sk/index.php/communications/article/view/1300.