1. Use and abuse of reference materials
2. Quevauviller, Ph., Kramer, K. J. M., Vercoutere, K. and Griepink, B. 1992. “The certification of the molalities of Cd, Cu, Pb, Mo, Ni and Zn in Off-shore Sea Water. CRM 403.”. 53Brussels: EEC/Community Bureau of Reference, report EUR 14061.
3. Kramer, C. J. M. 1988.Manual on Aquatic Ecotoxicology, Edited by: De Kruijf, H. A. M., De Zwart, D., Visvanathan, P. N. and Ray, P. K. 201–207. New Delhi: Allied Publ. PVT Ltd.
4. Estimating the discharge of contaminants to coastal waters by rivers: Some cautionary comments