1. Alexander M., 1961, Introduction to Soil Biology, John Wiley, New York.
2. Beyer M., 1969, Atmos. Absorp. Newsletter 8, 23.
3. Brosset C., 1973, Airborne acid, Ambio 2, 2?9.
4. Brosset C., Andreasson K., and Fern M., 1975, The nature and possible origin of acid particles observed at the Swedish west coast, Atmos. Environ. 9, 631?642.
5. Brosset C., 1976, Airborne particles: Black and White episodes, Ambio 5, 157?163.