1. M. Hebda and A. Wachal, Tribology (WNT, Warsaw, 1980) (in Polish)
2. S. Pytko, Investigating the Destruction Mechanism of Rolling Surfaces of Machines Elements (AGH, Cracow, 1967) (in Polish)
3. S. Pytko, M. Szczerek (1993) Tribologia 4/5:317 (in Polish)
4. IP 300/82, Rolling Contact Fatigue Tests for Fluids in a Modified Four-Ball Machine
5. W.O. Winer and H.S. Cheng, in: Wear Control Handbook, M.B. Peterson and W.O. Winer, eds. (ASME, New York, 1980)