1. M. W. Miller and C. G. Berg., eds., “Chemical Fallout,” C. E. Thomas, Springfield, III. (1969).
2. A. L. Hammond, Chemical Pollution: Polychlorinated Biphenyls, Science 175, 175 (1972).
3. P. C. Blokker, Recent Air Pollution Problems, in “Environmental Quality and Safety” (F. Coulston and F. Korte, eds.), Vol. 2, pp. 38–46, Georg Thieme, Stuttgart (1973).
4. Swedish Secretariat, Sulphur polution across national boundaries. Ambio 1, 15–20 (1972).
5. H. Babich and G. Stotzky, Air pollution and microbial ecology, Crit. Rev. Environ. Controls, 129–152 (1973).