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2. C. Derappe, French pat. M 5263 (Sept. 1967); through Chem. Abstr., 71,81377(1969).
3. C. Derappe, French pat. 1,469,022 (Feb. 1967); through Chem. Absrr., 68,68997(1968).
4. J. J. Piala and H. L. Yale, U. S. pat. 3,142,022 (July1964);through Chem. Abstr., 61,8317(1964).