Kim, EJ. (2010). How much sex is healthy? The pleasures of asexuality. in J. M. Metzl and A. Kirkland (eds). Against Health: How Health Became the New Morality. New York: New York University Press. pp. 157-169
The book that this chapter appears in was just recently published, and this chapter addresses issues pertaining to asexuality and disability. Parts of the book can be found in google books. For those unable to get a print version, it should be possible to obtain a copy by emailing the author.