6Jaeschke M,Schley P,Janssen-van R R. Thermodynamic research improves energy measurement in natural gas [J]. International Journal of Thermophysics ,2002,23 (2) : 1013 -1031.
7ISO 6976 : 1995, Natural gas-Calculation of calorific value, density, relative density and Wobbe index from composition [S].
8Attari A, Klass D L. Natural gas energy measurement[ M ]. Taylor & Francis Group,2005.