1. Rue, Vincent, Priscilla Coleman, James Rue, David Reardon, Medical Science Monitor 2004; 10(10):SR5-16
2. http://www.ewtn.com/library/mary/beretta.htm, Taken from: L’Osservatore Romano Weekly Edition in English 27 April 1994, L’Osservatore Romano is the newspaper of the Holy See. The Weekly Edition in English is published for the US by: The Cathedral Foundation L’Osservatore Romano English Edition, 320 Cathedral Street, Baltimore, MD 21201, Subscriptions: Tel: (410) 547-5315, Fax: (410) 332-1069, Email: firstname.lastname@example.org
3. Pregnancy Facts Page. All Facts are drawn from The Endowment For Human Development (www.ehd.org) – Improving lifelong health one pregnancy at a time.