@inproceedings{bridges2015:9,
  author      = {Roelofs, Rinus},
  title       = {The Concept of Elevation applied to Flat Tiling Patterns},
  pages       = {9--16},
  booktitle   = {Proceedings of Bridges 2015: Mathematics, Music, Art, Architecture, Culture},
  year        = {2015},
  editor      = {Delp, Kelly and Kaplan, Craig S. and McKenna, Douglas and Sarhangi, Reza},
  isbn        = {978-1-938664-15-1},
  issn        = {1099-6702},
  publisher   = {Tessellations Publishing},
  address     = {Phoenix, Arizona},

  url         = {http://archive.bridgesmathart.org/2015/bridges2015-9.html}
}