Thieme published a chapter on Voice modification in "Gender Affirmation Medical and Surgical Perspectives",
edited by Christopher Salgado, Stan Monstrey and Miroslav Djordjevic. This chapter, from pages 31-50, covers several different approaches to modifying the male to female voice surgically.
It has a complete set of photographs of Feminization Larynoplasty along with details about the surgical technique.
The textbook is available from the publisher and on Amazon.com.