Random number generators are provided in the form of one or more ten-sided dice, made up of two, identical, regular, five-sided pyramids with planar bases face to face. The faces of each die on opposite sides of the equatorial plane defined by the bases are offset 36.degree. from one another. The equatorial...http://www.google.fr/patents/US4239226?utm_source=gb-gplus-shareBrevet US4239226 - Random number generator
