World Bank Group. (1999). Natural gas: Private sector participation and market development. World Bank Group.
芝加哥风格引文World Bank Group. Natural Gas: Private Sector Participation and Market Development. Washington, D.C: World Bank Group, 1999.
MLA引文World Bank Group. Natural Gas: Private Sector Participation and Market Development. World Bank Group, 1999.
警告：这些引文格式不一定是100％准确.