Hoff and Overgaard & World Tourism Organization. (1992). Tourism master plan for the Philippines. World Tourism Organization.
Citazione stile Chigago Style (17a edizione)Hoff and Overgaard e World Tourism Organization. Tourism Master Plan for the Philippines. [Madridn]: World Tourism Organization, 1992.
Citatione MLA (9a ed.)Hoff and Overgaard e World Tourism Organization. Tourism Master Plan for the Philippines. World Tourism Organization, 1992.
Attenzione: Queste citazioni potrebbero non essere precise al 100%.