World Tourism Organization. (1983). Development of a system of statistical indicators for travel and tourism. The Organization.
芝加哥风格引文World Tourism Organization. Development of a System of Statistical Indicators for Travel and Tourism. Madrid: The Organization, 1983.
MLA引文World Tourism Organization. Development of a System of Statistical Indicators for Travel and Tourism. The Organization, 1983.
警告：这些引文格式不一定是100％准确.