1. The World Professional Association for Transgender Health The Standards of Care for the Health of Transsexual, Transgender, and Gender Nonconforming People th http://www.wpath.org/documents/Standards%20of%20Care%20V7%20-%202011%20WPATH.pdf
2. Care of transsexual persons;Gooren;N. Engl. J. Med.,2011
3. The intersexual state;Hirschfeld;Jahrb. Sex. Zwischenstufen.,1923