1. AL-BADRI A. S. 1977. A hydrogeochemical investigation of the Askrigg Block (northern Pennine orefield). Unpublished Ph.D. thesis, University of Sheffield, 549 pp.
2. ANON . 1961. European standards for drinking water. World Health Organisation, Geneva, 52 pp.
3. Statistical appraisal of the occurrence of lead mines in the northern Pennines;BOZDAR;Trans. Instn Min. Metall.,1972
4. CRUZAT A. C. E. 1972. Application of regional stream sediments geochemistry in forecasting base metal prospecting, northern England. Unpublished Ph.D. thesis, University of London, 364 pp.
5. DAVIS J. C. 1973. Statistics and data analysis in geology. J. Wiley, New York, 550 pp.