Here's a link to a 2011 paper on transgender student athletes. It's kind of long--about 60 pages--but it might be of interest to someone here. You can download the paper without a username if you hit "download anonomously".
http://papers.ssrn.com/sol3/papers.cfm?abstract_id=1646059&download=yes (http://papers.ssrn.com/sol3/papers.cfm?abstract_id=1646059&download=yes)