APA (7th ed.) Citation

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 (9th ed.) Citation

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

Warning: These citations may not always be 100% accurate.