Cerebral venous sinus thrombosis in a woman using the etonogestrel-ethinyl estradiol vaginal contraceptive ring: a case report.

Dunne C, Malyuk D, Firoz T.

J Obstet Gynaecol Can. 2010 Mar;32(3):270-3.

https://www.ncbi.nlm.nih.gov/pubmed/20500972