Name Info Provider Link
subscription/membership/fee required Elsevier Science https://linkinghub.elsevier.com/retrieve/pii/S1386-5056(18)30601-4
Childbirth free resource MedlinePlus Health Information https://medlineplus.gov/childbirth.html
subscription/membership/fee required ClinicalKey https://www.clinicalkey.com/content/playBy/pii?v=S1386-5056(18)30601-4