British Geomorphological Research Group: Technical Bulletins No. 28. Palaeohydrology of River Basinsby L. Starkel; J. B. Thornes;British Geomorphological Research Group: Technical Bulletins No. 29. Shorter Technical Methods (IV)by S. Trudgill;British Geomorphological Research Group: Technical Bulletins No. 30. Methods of Locating Slip Surfaces in Landslidesby J. N. Hutchinson