1. Gold, T., “Earth Outgassing of Methane”, Methane Fuel for the Future, Editor P. McGeer and E. Durbin, Plenum Press, 1982.
2. Karim, G. A. and Wierzba, I., “Comparative Studies of Methane and Propane as Fuels for Spark Ignition and Compression Ignition Engines”, SAE Trans. Vol. 92, Paper # 831196 (SP — 548), 1983.
3. Karim, G. A., Wierzba, I. and Al-Alousi, Y., “ Methane-Hydrogen Mixtures as Fuels”, Intl. J. of Hydrogen Energy, Vol. 21, No. 17, pp. 625–631, 1996.
4. Gao, J. and Karim, A. G., “A Predictive Model for Knock in Spark Ignition Engines”, SAE paper # 922366 (SP — 937), 1992.
5. Karim, A. G., Gao, J. and Alizadeh Atter, A., “A Predictive Approach to Spark Ignition Engine Performance Fuelled with Common Gaseous Fuels and Their Mixtures”, Proceeding of the 17th Annual Fall Technical Conference of the ASME Internal Combustion Division, Vol. 2, pp. 59–64, 1995.