Calayag, K. (2020). Duterte wants all Filipinos vaccinated against Covid-19. Manila Times.
Chicago-referens (17:e uppl.)Calayag, Keith. "Duterte Wants All Filipinos Vaccinated Against Covid-19." Manila Times 2020.
MLA-referens (9:e uppl.)Calayag, Keith. "Duterte Wants All Filipinos Vaccinated Against Covid-19." Manila Times, 2020.
Varning: dessa hänvisningar är inte alltid fullständigt riktiga.