1. CASIDA, J. E., R. L. HOLMSTRAD, S. KHALIFA, J. R. KNOX, T. OHSAWA, K. J. PALMER, and R. Y. WONG: Science183, 520 (1974).
2. FITZHUGH, O. G., and A. A. NELSON: Fed. Proc.10, 295 (1951).
3. GUYER, G. E., P. L. ADKISSON, K. DUBOIS, C. MENZIE, H. P. MICHOLSON, G. ZWEIG, and C. L. DUNN:Toxaphene Status Report, Environmental Protection Agency, Washington, D. C. (1971).
4. HOLLANDER, M., and D. A. WOLFE: Nonparametric Statistical Methods, John Wiley and Sons, New York, pgs. 71, 120 (1973).
5. JOHNSON, D. W., G. F. LEE, and D. SPYRIDAKIS: Air and Water Pollut. Int. J.10, 55 (1966).