1. Abdazimov, A. D., 1989. Assessment of the working conditions and health susceptibility of workers in the production of copper, zinc, and lead, Gig. Tr. Prof. Zabol. 5:18–21. (Russian).
2. Abernathy, C. O., Cantilli, R., Du, J. T., and Levander, O. A., 1993. Essentially versus toxicity. Source considerations in risk assessment of essential trace elements, in: Hazard Assessment of Chemicals (J. Saxena, ed.), Taylor and Francis, Washington, D.C., pp. 81–113.
3. ACGIH (American Conference of Governmental and Industrial Hygienists), 1990-1991. Threshold limit value for chemical substances and physical agents and biological exposure. ACGIH, Cincinnati, Ohio. Cited by Ennever (1994).
4. Adloff, J.-R, and Guillaumont, R., 1993. Fundamentals of Radiochemistry, CRC Press, Boca Raton, Florida, pp. 126–135.
5. Ahrland, S., 1965. Strong and weak acids and bases, Svensk. Kern. Tidskr. 77:584–597.