Geological survey of Great Britain (England and Wales) 1:50 000 series Sheet 223, Braintree : solid and drift edition / Geological survey of Great Britain (England and Wales) ; made and published by the Director General of the Ordnance Survey, Southampton, for the Institute of Geological Sciences ; Surveyed on the six-inch scale by M.J. Heath, R.A. Ellison, R.D. Lake [et al.] ; S.C.A. Holmes and W.A. Read, Disctrict Geologists / Southampton : Ordnance Survey , 1982