Source

The Canberra Times (an Australian newspaper), based on Bettina Arndt’s book The Sex Diaries

http://www.canberratimes.com.au/news/opinion/editorial/general/women-need-to-say-yes-to-sex/1447294.aspx?storypage=0

Arndt backs her own findings by citing research by Professor Rosemary Bassoncites.