Manual of petroleum measurement standards chapter 11-physical properties data : section 2, part 5-a simplified vapor pressure correlation for commercial ngls / prepared for American Petroleum Institute, 1220 L Street, NW, Washington, D.C. 20005, ASTM International, 100 Barr Harbor Drive, West Conshohocken, Pa., 19428, Gas Processors Association, 6526 E. 60th Street, Tulsa, OK 74145. (ASTM manual series ;, 2007)