1. BACHE,et al.: Science172, 951–952 (1971).
2. BLIGH, E.G.: Manuscript report series No. 1088. Freshwater Institute. Winnipeg 19, Manitoba (1970).
3. GEBHARDS, S.: KLEIN,et al.: J. of the Idaho Acad. of Sci. Special Research Issue. No. 2, 44–53, (1971).
4. GEBHARDS, SHIELDS,et al.: Mercury Levels in Idaho Fishes and Aquatic Environment. State of Idaho Fish and Game Department and Department of Health Publication (1970–1971).
5. HOROWITZ, E. (ed): Official methods of analysis of association of official analytical chemists, lled. Washington, D.C. 24.060 and 24.062 (1970).