1. T. Wang, A. Brockhaus, Anal. Chim. Acta II, 55–60 (1976).
2. H.-J. Moriske, I. Block, H. Rüden, Forum Städte-Hyg.35, 113–121 (1984).
3. F. Pott, R. Tomingas, A. Brockhaus, F. Huth, Zbl. Bakt. Hyg. I. Abt. Orig. B.170, 17–34 (1980).
4. N. Seemayer, N. Manojlovic, Toxicology17, 177–182 (1980).
5. W. Dehnen, N. Pitz, R. Tomingas, Cancer Letters4, 5–12 (1977).