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2. Gore, W. S.: Statistical Methods for Chemical Experimentation. Interscience: New York (1952).
3. Gunther, F. A., and R. C. Blinn: Analysis of Insecticides and Acaricides. Interscience: New York-London (1955).
4. Huddleston, E. W., K. H. Thompson, G. G. Gyrisco, D. J. Lisk, T. W. Kerr, and C. E. Alney: Sampling experimental plots of alfalfa for insecticide residues. J. Econ. Entomol. 53, 1078 (1960).
5. Lykken, L., L. E. Mitchell, and S. M. Woogerd: Sampling crops for residue analysis. J. Agr. Food Chem. 5, 501 (1957).