2
Published 2000
National Academy Press

3
Published 2008
RCOG Press

4
by Gaynes, Bradley N.
Published 2005
U.S. Dept. of Health and Human Services, Public Health Service, Agency for Healthcare Research and Quality

5
by Stoto, Michael A.
Published 1999
National Academy Press

7
by Viswanathan, Meera
Published 2006
Agency for Healthcare Research and Quality, U.S. Department of Health and Human Services