Varga : A complex process for hydrogenating brown coal and high-molecular-weight asphaltenes. The process uses hydrogen at a high pressure, in the presence of an iron oxide catalyst
Comyns, Alan E. Dictionary, Encyclopedic Dictionary of Named Processes in Chemical Technology (3rd ed.), Alan E. Comyns (Ed.), Boca Raton, FL, CRC Press LLC, USA 2000, http://worldtracker.org/media/library/Science/Chem istry/Synthesis/Encyclopedic%20Dictionary%20of%20N amed%20Processes%20in%20Chemical%20Technology.pdf, (Named Chem Procss - Amer) {35}