Population news service. Population Center Foundation.
芝加哥风格引文Population News Service. Makati, Rizal: Population Center Foundation.
MLA引文Population News Service. Population Center Foundation.
警告：这些引文格式不一定是100％准确.
APA引文
Population news service. Population Center Foundation.
芝加哥风格引文Population News Service. Makati, Rizal: Population Center Foundation.
MLA引文Population News Service. Population Center Foundation.