Special thanks to Stork Radio.com for freely providing their knowledge and expertise on fetal dopplers and ultrasound. They we're an invaluable tool in gathering the information for this site.

Dr Joseph Woo, A Short History of the Development of Ultrasound in Obstetrics and Gynecology, http://www.ob-ultrasound.net/history1.html ,

Vince Lepak. PT, MPH, CWS, Ultrasound, http://moon.ouhsc.edu/llepak/

http://www.birth.com.au

http://www.frca.co.uk

http://www.marchofdimes.com

http://www.fda.gov

http://www.aium.com

http://www.unborn.com