Székely É.; Gyöngyös-Radnai Zs.; Székely R.: Grinding of Mecsek coals in presence of additives, II. In: Acta mineralogica-petrographica, (32). pp. 85-90. (1991)
Székely É.; Székely R.; Gyöngyös-Radnai Zs.: Grinding of Mecsek coals in presence of additives I. In: Acta mineralogica-petrographica, (31). pp. 89-95. (1990)