APA引文

Billings, E., & Westmore, A. (2007). Metode Ovulasi Billing. Cara Mengatur Kesuburan. KPG.

Chicago Style (17th ed.) Citation

Billings, Evelyn, and Ann Westmore. Metode Ovulasi Billing. Cara Mengatur Kesuburan. KPG, 2007.

MLA引文

Billings, Evelyn, and Ann Westmore. Metode Ovulasi Billing. Cara Mengatur Kesuburan. KPG, 2007.

警告：這些引文格式不一定是100％准確.