North Atlantic Treaty Organization Scientific Affairs Division, NATO Advanced Research Workshop on Security of natural gas supply through transit countries, Hetland, J., & Gochitashvili, T. (2004). Security of natural gas supply through transit countries. Kluwer Academic Publishers.

North Atlantic Treaty Organization Scientific Affairs Division, NATO Advanced Research Workshop on Security of natural gas supply through transit countries, Jens Hetland, and Teimuraz Gochitashvili. Security of Natural Gas Supply Through Transit Countries. Boston: Kluwer Academic Publishers, 2004.

North Atlantic Treaty Organization Scientific Affairs Division, et al. Security of Natural Gas Supply Through Transit Countries. Kluwer Academic Publishers, 2004.