Ryan, C. (2006). Recreational tourism: Demand and impacts. Viva books.
シカゴスタイル引用形Ryan, Chris. Recreational Tourism: Demand and Impacts. New Delhi: Viva books, 2006.
MLA引用形式Ryan, Chris. Recreational Tourism: Demand and Impacts. Viva books, 2006.
警告: この引用は必ずしも正確ではありません.