@inproceedings{bridges2007:333,
  author      = {Palmer, James Dean},
  title       = {Planar Symmetry with Turtles},
  pages       = {333--334},
  booktitle   = {Bridges Donostia: Mathematics, Music, Art, Architecture, Culture},
  year        = {2007},
  editor      = {Sarhangi, Reza and Barrallo, Javier},
  isbn        = {0-9665201-8-1},
  issn        = {1099-6702},
  publisher   = {Tarquin Publications},
  address     = {London},

  url         = {http://archive.bridgesmathart.org/2007/bridges2007-333.html}
}