1. The sequence stratigraphic and environmental context of primitive vertebrates: Harding Sandstone, Upper Ordovician, Colorado, USA;Allulee;Palaios,2005
2. The Old Red Sandstone of Brown Clee Hill and the adjacent area, I: Stratigraphy;Ball;Bulletin of the British Museum (Natural History), Geology,1961
3. Lithostratigraphy of the Old Red Sandstone successions of the Anglo-Welsh Basin;Barclay,2014
4. The Baltic region;Bassett;National Museum of Wales, Geological Series,1989
5. Silurian ostracoderms from Washington Land (North Greenland), with comments on cyathaspid structure, systematics and phyletic position;Bendix-Almgreen;Rapport Grønlands Geologiske Undersøgelse,1986