WebMD. https://www.webmd.com/baby/guide/bleeding-during-pregnancy#1
Diakses pada September 2018NCBI. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2672226/ https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4064773/
Diakses pada September 2018Healthline. https://www.healthline.com/health/pregnancy/first-trimester-bleeding
Diakses pada 13 November 2020