Gaya APA

(UNWTO), W, T, O., (ETC), E, T, C. (2011). Handbook on Tourism Product Development ( hanya tersedia file pdf ) . Spanyol: World Tourism Organization.

Gaya MLA

(UNWTO), World, Tourism, Organization., (ETC), European, Travel, Commission. "Handbook on Tourism Product Development ( hanya tersedia file pdf )". Spanyol: World Tourism Organization, 2011. Text.