A Handbook of Celtic Ornament by John G. Merne
Courier Corporation, 2001 (originally 1980) ISBN 9780486419602
This is a simple but complete course in the construction and development of Celtic ornamental knot interlacings for Art and Craft students, with over 700 illustrations. For those keen to use knot patterns in the graphic arts, the systematically developed instruction in this book is invaluable.