Mercury News. https://www.mercurynews.com/2018/06/25/the-best-time-of-day-to-have-sex-according-to-science/#:~:text=But%20if%203%20p.m.%20doesn,perfectly%20tuned%2Dup%20body%20clock.
Diakses pada 30 Desember 2020Very Well Family. https://www.verywellfamily.com/when-and-how-often-to-have-sex-to-get-pregnant-1960289
Diakses pada 30 Desember 2020