1. Allen JRL, Fulford MG (1986) The wentlooge level: a Romano–British saltmarsh reclamation in southeast wales. Britannia 17:91–117
2. British Geological Survey (1975) Sheet 249 Newport, 1:50,000 Series Geological Survey of England and Wales
3. British Geological Survey (1980) Sheet 279 Weston-super-Mare, 1:50,000 Series Geological Survey of England and Wales
4. British Geological Survey (1986a) Sheet 264 Portishead, 1:50,000 Series Geological Survey of England and Wales
5. British Geological Survey (1986b) Sheet 263 Cardiff, 1:50,000 Series Geological Survey of England and Wales