19.U.S. Preventive Services Task Force. Screening for Hepatitis B Virus Infection in Pregnancy: U.S. Preventive Services Task Force Reaffirmation Recommendation Statement. AHRQ Publication No. 09-05134-EF-1, June 2009. http://www.uspreventiveservicestaskforce.org/uspstf09/hepb/hepbpgrs.htm
20.U.S. Preventive Services Task Force. Screening for Osteoporosis: Recommendation Statement. AHRQ Publication No. 10-05145-EF-2, January 2011. http://www.uspreventiveservicestaskforce.org/uspstf10/osteoporosis/osteors.htm
21.U.S. Preventive Services Task Force. Screening for Rh (D) Incompatibility: Recommendation Statement. February 2004. http://www.uspreventiveservicestaskforce.org/3rduspstf/rh/rhrs.htm