^Krötenheerdt, O. "Die homogenen Mosaike n-ter Ordnung in der euklidischen Ebene. I." Wiss. Z. Martin-Luther-Univ. Halle-Wittenberg, Math.-Natur. Reihe 18, 273-290, 1969.
^Grünbaum, B. and Shephard, G. C. Tilings and Patterns. New York: W. H. Freeman, 1986.
Williams, Robert. The Geometrical Foundation of Natural Structure: A Source Book of Design. Dover Publications, Inc. 1979: 41. ISBN 0-486-23729-X.
Grünbaum, Branko ; and Shephard, G. C. Tilings and Patterns. New York: W. H. Freeman. 1987. ISBN 0-7167-1193-1. (Chapter 2.1: Regular and uniform tilings, p.58-65)
Williams, Robert. The Geometrical Foundation of Natural Structure: A Source Book of Design. Dover Publications, Inc. 1979. ISBN 0-486-23729-X. p38