1. K. H. Altgelt, and M. M. Boduszynski ,Composition and Analysis of Heavy Petroleum Fractions (New York: Marcel Dekker,1993 ).
2. K. van Nes, and H. van Westen ,Aspects of the Constitution of Mineral Oils (New York: Elsevier,1951 ).
3. W.S. Moon, Y.R. Cho, and J. S. Chun , "Application of High Quality (Group II, III) Base Oils to Specialty Lubricants," Paper presented at the 6th annual Fuels and Lubes Asia Conference,Singapore,January28,2000 .