Serhiy Buriakovskyi, Borys Liubarskyi, Artem Maslii, Danylo Pomazan, and Tatyana Tavrina. “Research of a Hybrid Diesel Locomotive Power Plant Based on a Free-Piston Engine”. Communications - Scientific Letters of the University of Zilina, Vol. 22, no. 3, July 2020, pp. 103-9, doi:10.26552/com.C.2020.3.103-109.