1. (1) (a) Pollution of Rivers Act , 1876 .
2. (2)b Fisheries Act, 1891 .
3. (3)(c) Salmon and Freshwater Fisheries Bill, 1922 .
4. (4)RobertHunt(1848 ). Notices of the History of Lead-Mines . Mem. Geol. Soc..
5. (5)O. T. Jones(1922 ). Special Reports on the Mineral Resources of Great Britain . Mem. Geol. Survey.