1. Japanese official method.
2. W. Hortz, “Official Methods of Analysis of AOAC,” 10th Ed., AOAC, Washington, 1965, p. 50.
3. WHO, “Specifications for Pesticides,” 2nd Ed., WHO, Jeneva, 1961, p. 54.
4. H. G. Viene, “Chemistry of Acetylenes,” Marcel Decker, New York, 1969, p. 365.