Παραπομπή APA

World Tourism Organization. (1992). Quidelines: Development of national parks and protected areas for tourism. Madrid: World Tourism Organization.

Παραπομπή Chicago Style

World Tourism Organization. Quidelines: Development of National Parks and Protected Areas for Tourism. Madrid: World Tourism Organization, 1992.

Παραπομπή MLA

World Tourism Organization. Quidelines: Development of National Parks and Protected Areas for Tourism. Madrid: World Tourism Organization, 1992.

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