1. ASTM Test Method D 5307. Test Method for Determination of Boiling Range Distribution of Crude Petroleum by Gas Chromatography.
2. ASTM Test Method D 4530. Test Method for Determination of Carbon Residue (Micromethod).
3. Butler, R. M. and Mokry, I. J. 1993. SPE 25452, Presented in Productions Operations Symposium. March 21–231993, Oklahoma City, USA. and references therein
4. Duerksen, J. H. and Eloyan, A. M. 1995. Proceeding 6th UNITAR Int. Conf. On Heavy Crude and Tar Sands. Feb.12–171995, Houston, Texas, USA. pp.353 and references therein