British Geomorphological Research Group: Research Monographs No. 1. Soil Pipes and Pipeflow: A Hydrological Study in Upland Walesby K. Gilman; M. D. Newson;British Geomorphological Research Group: Research Monographs No. 2. Water-Rock Interactionsby J. M. Verstraten;British Geomorphological Research Group: Research Monographs No. 3. The Nature of Soil Piping: A Review of Researchby J. A. A. Jones;British Geomorphological Research Group: Research Monographs No. 4. Periglacial Mass-Wasting: A Review of Researchby C. Harris