1. J. O. NRIAGAU, C. I. DAVIDSON (Eds), Toxic Metals in the Atmosphere, John Wiley and Sons, New York, 1986.
2. G. D. CLAYTON, F. E. CLAYTON, Pattys Industrial Hygiene and Technology, Vol. 2, Wiley Interscience, New York, 1982.
3. A. C. STERN, Air Pollution, Vol. 3, Measurement, Monitoring and Surveillance of Air Pollution, 3rd. ed., Academic Press, New York, 1976.
4. J. ZHANG, J. BILLET, M. NAGELS, R. DAMS, Sci. Total Environ. 30 (1983) 167.
5. M. S. AKANNI, V. O. OGUGABUAJA, W. D. JAMES, J. Radioanal. Chem., 79 (1983) 197.