Cita APA

Wang, H., & Whittington, D. (2000). Willingness to pay for air quality improvements in Sofia, Bulgaria. Washington: World Bank.

Citación estilo Chicago

Wang, Hua, and Dale Whittington. Willingness to Pay for Air Quality Improvements in Sofia, Bulgaria. Washington: World Bank, 2000.

Cita MLA

Wang, Hua, and Dale Whittington. Willingness to Pay for Air Quality Improvements in Sofia, Bulgaria. Washington: World Bank, 2000.