1. Albert, R. E., Blodgett, F. M., Brown, T. and Bryson, R. A.et al.: 1972,Lead, Airborne Lead in Perspective, National Academic of Science, Washington DC, p. 18.
2. Atkins, P. R.: 1969,J. Air Pollut. Control Assoc. 19, 591.
3. U.S. Environmental Protection Agency, Environmental Criteria and Assessment Office: 1983,Air Quality Criteria for Lead, vol. 11. Sampling and analytical methods for environmental lead. 53.
4. Bullin, J. A., Bower, S. C., Hinz, M. and Moe, R. D.: 1985,J. Air Pollut. Control Assoc. 35, 355.
5. Burton, R. M. and Suggs, J. C.: 1984,Philadelphia Roadway Study, Research Triangle Park, NC: U.S. Environmental Protection Agency, Environment Monitoring Systems Laboratory; EPA report no: 600/4-84-070.