@inproceedings{bridges2010:114,
  author      = {J\'{a}nos Erd\H{o}s},
  title       = {Sphaerica: Interactive Spherical Geometry Software},
  pages       = {443--446},
  booktitle   = {Proceedings of Bridges 2010: Mathematics, Music, Art,
                 Architecture, Culture},
  year        = {2010},
  editor      = {George W. Hart and Reza Sarhangi},
  isbn        = {978-0-98460-420-3},
  issn        = {1099-6702},
  publisher   = {Tessellations Publishing}
}