Du Val, Patrick Homographies, quaternions, and rotations. (English) Zbl 0128.15403 Oxford Mathematical Monographs. Oxford: At the Clarendon Press 1964. XIV, 116 p. (1964). Page: −5 −4 −3 −2 −1 ±0 +1 +2 +3 +4 +5 Show Scanned Page Cited in 3 ReviewsCited in 92 Documents Keywords:analytical geometry, projective geometry PDF BibTeX XML OpenURL Online Encyclopedia of Integer Sequences: Number of 4-dimensional point groups of order n. Number of 4-dimensional chiral point groups of order n.