1. Pesticide Analytical Manual, U. S. Dept. of Health, Education, and Welfare, Vol. 1, Section 230.12.
2. Porter, P. E., Analytical Methods for Pesticides, Plant Growth Regulators, and Food Additives, II, 351, (1964).
3. Ibid. 354.
4. Hindin, E., Analytical Methods for Pesticides, Plant Growth Regulators, and Food Additives, I, 89, (1967).