World Tourism Organization Market Intelligence and Promotion Section Sustainable Development of Tourism Section & World Tourism Organization. (2001). The German ecotourism market. World Tourism Organization.
Παραπομπή σε μορφή Chicago (17η εκδ.)World Tourism Organization Market Intelligence and Promotion Section Sustainable Development of Tourism Section και World Tourism Organization. The German Ecotourism Market. Madrid, Spain: World Tourism Organization, 2001.
Παραπομπή σε μορφή MLA (9th εκδ.)World Tourism Organization Market Intelligence and Promotion Section Sustainable Development of Tourism Section και World Tourism Organization. The German Ecotourism Market. World Tourism Organization, 2001.
Πρόσοχή: Οι παραπομπές μπορεί να μην είναι 100% ακριβείς.