FamousTexans.com: Mary Martin
   Biography of Mary Martin; musical theater singer, dancer, and mother of actor, Larry Hagman.
   http://www.famoustexans.com/marymartin.htm

IMDb: Mary Martin
   Profile, filmography, television appearances, awards, and images.
   http://us.imdb.com/name/nm0552756/

Wikipedia.com: Mary Martin
   Credits for her stage, television, and film work, as well as her many awards.
   http://www.wikipedia.org/wiki/Mary_Martin