@PhdThesis{Hammond2007Ladder,
  author = 	 {Tracy Anne Hammond},
  title = 	 {LADDER: A Perceptually-based Language to Simplify Sketch Recognition User Interface Development},
  school = 	 {Massachusetts Institute of Technology},
  year = 	 {2007},
  OPTkey = 	 {},
  OPTtype = 	 {},
  address = 	 {Cambridge, MA},
  month = 	 {January},
  OPTnote = 	 {},
  OPTannote = 	 {}
}