Wang, H., & Whittington, D. (2000). Willingness to pay for air quality improvements in Sofia, Bulgaria. World Bank.
芝加哥风格引文Wang, Hua, 与 Dale Whittington. Willingness to Pay for Air Quality Improvements in Sofia, Bulgaria. Washington, D.C: World Bank, 2000.
MLA引文Wang, Hua, 与 Dale Whittington. Willingness to Pay for Air Quality Improvements in Sofia, Bulgaria. World Bank, 2000.
警告：这些引文格式不一定是100％准确.