1. British Regional Geology: North Wales;George,1961
2. On the origin of slaty cleavage;Sorby;Edinb. New Phil. J.,1853
3. On the theory of the origin of slaty cleavage;Sorby;Phil. Mag.,1856
4. The relationship of slaty cleavage and kindred structures to tectonics;Wilson,1946
5. Geology of some Classic British Areas—Snowdonia;Williams;Geologists Association Guide No. 28,1959