@inproceedings{bridges2006:503,
  author      = {Wills, Tony},
  title       = {D-Forms: 3D Forms from Two 2D Sheets},
  pages       = {503--510},
  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/bridges2006-503.html}
}