World Bank & World Bank. (2005). A guide to competitive vouchers in health. World Bank.
Chicago-referens (17:e uppl.)World Bank och World Bank. A Guide to Competitive Vouchers in Health. Washington, DC: World Bank, 2005.
MLA-referens (9:e uppl.)World Bank och World Bank. A Guide to Competitive Vouchers in Health. World Bank, 2005.