Mathematical analysis of identical circles touching one another on the spherical polyhedrons analogous to Archimedean solids
Polydrons (Beauty of Three Dimensional Polyhedra Workshop)
Rank 3-4 Coxeter Groups, Quaternions and Quasicrystals
Gothic Cathedrals Pg 18 Pg 23 Pg 38 The abacus was one of the earliest calculating devices, a 'step-up' from the more primitive counting board. This.
Gothic Cathedrals Pg 18
