Centers for Disease Control and Prevention. Assisted Reproductive Technology 2012.
http://www.cdc.gov/art/pdf/2012-report/art_2012_graphs_and_charts_final.pdf
Centers for Disease Control and Prevention. Assisted Reproductive Technology 2012.
http://www.cdc.gov/art/pdf/2012-report/art_2012_graphs_and_charts_final.pdf