APA (7e ed.) Bronvermelding

Alfonso, O. E. S., Rieza, C. H. S., & Alampay, R. B. A. The product life cycle theory and tourism in the Philippines: Case studies of Pagsanjan and Baguio City.

Chicago (17e ed.) Bronvermelding

Alfonso, Oscar Emel S., Carmela Helene S. Rieza, en Ramon Benedicto A. Alampay. The Product Life Cycle Theory and Tourism in the Philippines: Case Studies of Pagsanjan and Baguio City.

MLA (9e ed.) Bronvermelding

Alfonso, Oscar Emel S., et al. The Product Life Cycle Theory and Tourism in the Philippines: Case Studies of Pagsanjan and Baguio City.