International Union of Official Travel Organisations. (1971). Methodology for annual and medium-term forecasts. International Union of Official Travel Organisations.
Chicago Style (17th ed.) CitationInternational Union of Official Travel Organisations. Methodology for Annual and Medium-term Forecasts. Geneva: International Union of Official Travel Organisations, 1971.
MLA引文International Union of Official Travel Organisations. Methodology for Annual and Medium-term Forecasts. International Union of Official Travel Organisations, 1971.
警告:這些引文格式不一定是100%准確.