1. Callaghan, J., Trans. Twenty-sixth N. Amer. Wildl. Nat. Res. Conf., 328 (1961).
2. Mackin, J. G., Prog. Rep., Texas A and M Res. Found. Coll. Stn, Texas (1950).
3. ZoBell, C. E., Internal. J. Air Wat. Pollut., 7, 173 (1963).
4. Report DASI/CS1/67.100 (1st revision) (OECD).
5. Becacos-Kontos, T., thesis, Univ. Athens (1967).