@inproceedings{bridges2014:481,
  author      = {Gelatti, Gabriele},
  title       = {On Colouring Sequences of Digital Roots},
  pages       = {481--482},
  booktitle   = {Proceedings of Bridges 2014: Mathematics, Music, Art, Architecture, Culture},
  year        = {2014},
  editor      = {Greenfield, Gary and Hart, George and Sarhangi, Reza},
  isbn        = {978-1-938664-11-3},
  issn        = {1099-6702},
  publisher   = {Tessellations Publishing},
  address     = {Phoenix, Arizona},

  url         = {http://archive.bridgesmathart.org/2014/bridges2014-481.html}
}