Kováčik, Jaroslav Effect of Composition on Friction Coefficient of Cu-Graphite Composites. Emmer, Štefan, 1948-. Bielek, Jozef, 1939-. Keleši, Ľubomír, 1949- In: Wear. -- Vol. 265, No. 3-4 (2008), s.417-421.