Some for the Reference Library. I really should be doing a PhD in this...
1966 : H. Benjamin - The Transsexual phenomenon - The Etiology of Transsexualism
1998: Factors predictive of regret in sex reassignment.
2005: Sexual and physical health after sex reassignment surgery
2009: GID in Children and Adolescents (PDF)
2010: Hormonal therapy and sex reassignment: a systematic review and meta-analysis of quality of life and psychosocial outcomes
2011 :Long-Term Follow-Up of Transsexual Persons Undergoing Sex Reassignment Surgery: Cohort Study in Sweden
2011: Primary Care Protocol for Transgender Patient Care: Evidence-Based Transgender Medicine
Evidence-based medicine. At last. Well, a start on it, anyway. Most of the papers on the subject are less than 15 years old.