1. Veiga, M. M. & Meech, J. A. Proc. Int. Symp. Al in Mat. Process. Edmonton, 107–118 (1992).
2. Ferreira, R. C. & Appel, L. E. EstudoseDocumentos Ser. 13, (CETEM/CNPq, Rio de Janerio, 1991) (in Portuguese).
3. GEDEBAM—Report for the Commission of the European Communities. (GEDEBAM and SOL 3 groups, Brazil— Switzerland—UK (1992).
4. Malm, O. thesis, Univ. Federal Rio de Janeiro (1991) (in Portuguese).
5. Jonasson, I. & Boyle, R. W. in Effects of Mercury in the Canadian Environment 28–49 (National Research Council of Canada, Ottawa, 1979).