Wikimedia
Wikipedia: Placenta
A brief but informative description of the placenta. Includes various links to further explain terminology used in the description.
American Academy of Family Physicians
Aafp: American Family Physician: Examination of the Placenta
This detailed article from American Family Physician journal covers a number of topics ranging from the clinical characteristics of the normal placenta to potential abnormalities of the placenta. The text is supplemented with actual...