The sand and gravel resources of the country around Hertford, Hertfordshire description of 1:25000 resource sheet TL 31
Hopson, P. M.
Samuel, M. D. A.
Institute of Geological Sciences (Great Britain)
London HMSO
1982
At head of title: Institute of Geological Sciences
Bibl.
Map (1 folded sheet) in pocket
Sand
Gravel