Medical News Today. https://www.medicalnewstoday.com/articles/284275.php#11
Diakses pada 25 November 2019
Healthy Children. https://www.healthychildren.org/English/ages-stages/baby/sleep/Pages/A-Parents-Guide-to-Safe-Sleep.aspx
Diakses pada 25 November 2019
What to Expect. https://www.whattoexpect.com/first-year/sleep-solutions/newborn-baby-safe-sleep-practices/
Diakses pada 25 November 2019