Name Info Provider Link
Folic Acid free resource MedlinePlus Health Information https://medlineplus.gov/folicacid.html
subscription/membership/fee required Ovid Technologies, Inc. http://ovidsp.ovid.com/ovidweb.cgi?T=JS&PAGE=linkout&SEARCH=14615465.ui
subscription/membership/fee required Wiley https://onlinelibrary.wiley.com/resolve/openurl?genre=article&sid=nlm:pubmed&issn=0091-2700&date=2003&volume=43&issue=12&spage=1299