1. 1(a) A. H. Cottrell , Dislocations and Plastic Flow in Crystals . Clarendon Press, Oxford, 1956 (reprint of 1st edition). 223 pp.
2. (b) W. T. Read , Dislocations in Crystals . McGraw-Hill Book Co., Inc., New York, 1953 . 228 pp.Ceram. Abstr., 1953 , p.228 .
3. Plastic Deformation of Ceramic-Oxide Single Crystals
4. 3The indices given throughout are the Miller-Bravais indices based on the morphological hexagonal unit cell.