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.
Lua i Stíl Chicago (17ú heag.)Alfonso, Oscar Emel S., Carmela Helene S. Rieza, agus Ramon Benedicto A. Alampay. The Product Life Cycle Theory and Tourism in the Philippines: Case Studies of Pagsanjan and Baguio City.
Lua MLA (9ú heag.)Alfonso, Oscar Emel S., et al. The Product Life Cycle Theory and Tourism in the Philippines: Case Studies of Pagsanjan and Baguio City.
Rabhadh: Seans nach mbeach na luanna seo go hiomlán cruinn i ngach uile chás.