The geology of the N. W. part of Essex and the N.E. part of Herts. With parts of Cambridgeshire and Suffolk. (Explanation of sheet 47 of the map (one-inch) of the Geological survey of England and Wales) - Whitaker, William; Bennett, F. J.; Dalton, William Herbert; Penning, W. H. (Printed for H. M. Stationery off., 1878)
Keywords: Geology / England. / http://id.loc.gov/authorities/subjects/sh2008117917