Silver Well: sheet 54°N/02°E
Quaternary Geology, 1:250 000 series British Geological Survey and Geological Survey of The Netherlands.
Jeffery, D.H., P. Frantsen, C. Laban & R.T.E. Schüttenhelm, 1989
Quaternary Geology, 1:250 000 series British Geological Survey and Geological Survey of The Netherlands.
Jeffery, D.H., P. Frantsen, C. Laban & R.T.E. Schüttenhelm, 1989