1. Fertility and ageing;Collins;Hum Reprod Update,2005
2. Multiple births resulting from ovarian stimulation for subfertility treatment;Fauser;Lancet,2005
3. Progress we can be proud of: U.S. trends in assisted reproduction over the first 20 years;Toner;Fertil Steril,2002
4. Gunby J. Assisted reproductive technologies (ART) in Canada: 2008 results from the Canadian ART register. 2010; http://www.cfas.ca/images/stories/pdf/cartr_2008.pdf. Accessed July 2011.
5. Statistics Canada, Canadian Vital Statistics, Birth and Stillbirth Databases 3231 and 3234. CANSIM Tables number 102–4515. “Live births and fetal deaths (stillbirths), by type (single or multiple), Canada, provinces and territories, annual (number).” http://estat.statcan.gc.ca/cgi-win/CNSMCGI.pgm. Accessed July, 2011.