1. Gas Processors Suppliers Association Engineering Data Book, 10th ed., 1987. The GPSA offices are at 6526 East 60th Street, Tulsa, OK 74145.
2. Gas Processors Association Standard 2145. Same address as GPSA.
3. Gas Processors Suppliers Association Engineering Data Book, 11th ed., Electronic FPS Version.
4. International Energy Annual, Energy Information Administration, U.S. Department of Energy.
5. U.S. Crude Oil, Natural Gas and Natural Gas Liquids Reserves, Energy Information Administration, U.S. Department of Energy.