British regional geology: the Welsh borderland, by J. R. Earp [and] B. A. Hains. Based on previous editions by R. W. Pocock and T. H. Whitehead. 3d ed.
British regional geology: the Welsh borderland, by J. R. Earp [and] B. A. Hains. Based on previous editions by R. W. Pocock and T. H. Whitehead.