References+and+Sources

Escher on Escher, Exploring the Infinite, M.C. Escher, Harry N. Abrams, INc., Publishers, New York (1989) Illustrated Maths Dictionary, Judith De Klerk, Pearson Rigby, (2009) Symmetry Aspects of M.C. Escer's Periodic Drawings, Caroline H. MacGillavry, Bohn, Scheltma & Holkema, Utrecht (1976) The Tate Gallery an illustraed companion, The Tate Gallery Publications Department (1981) Making Mosaics, Martin Cheek, New Holland Publishers (UK) Ltd (2000)
 * R****eferences**


 * Links**

VELS Working mathematically []

349162 and SESBun2005 []

[] [] fractions tesselations