Indefa¬tigable: sheet 53°N/02°E
Quaternary Geology, 1:250 000 series British Geological Survey and Geological Survey of The Netherlands.
Cameron, T.D.J., C. Laban & R.T.E. Schüttenhelm, 1986
Quaternary Geology, 1:250 000 series British Geological Survey and Geological Survey of The Netherlands.
Cameron, T.D.J., C. Laban & R.T.E. Schüttenhelm, 1986