1. K. Bergman, W. Schneider, Chromatographia15, 631 (1982).
2. P.M. Williams, I. R. Whiteside, T. P. Jones, International Environment and Safety,15, (April 1981).
3. F. S. Sleva, Public Health Service Publication no 999 AP-11 H 1 (1965).
4. R. R. Miksch, D. W. Anthon, Amer. Ind. Hyg. Assoc. J.,43, 362 (1982).
5. Method 116 p. 303 in “Methods of air sampling and analysis APHA” Intersociety Committee, Second Edition,M. Katz, Ed., American Public Health Association Washington DC 20036 (1977).