@inproceedings{bridges2006:109,
  author      = {Kahn, Ken},
  title       = {A Program to Interpolate (and Extrapolate) between Turtle Programs},
  pages       = {109--114},
  booktitle   = {Bridges London: Mathematics, Music, Art, Architecture, Culture},
  year        = {2006},
  editor      = {Sarhangi, Reza and Sharp, John},
  isbn        = {0-9665201-7-3},
  issn        = {1099-6702},
  publisher   = {Tarquin Publications},
  address     = {London},

  url         = {http://archive.bridgesmathart.org/2006/bridges2006-109.html}
}