In proposition 17, book XII, Euclid constructed a polyhedron with rings, each consisting of faces. The special case, , was constructed by Campanus and is a 72-faced polyhedral sphere. During the Renaissance, it was as popular as the Platonic solids .
 P. R. Cromwell, Polyhedra, New York: Cambridge University Press, 1999 pp. 106–107. www.liv.ac.uk/~spmr02/book/index.html.
Wolfram Demonstrations Project
Published: December 19 2011