1. Threshold Limit Values for 1960
2. Zhitkova, A. S. 1936.Some Methods for the Detection and Estimation of Poisonous Gases and Vapors in the Air, 193–194. West Hartford, Conn.: Service to Industry. translated by J. B. Ficklen
3. Smelyanskiy, Z. B. and Ulanova, I. P. 1959.New Standards Regarding the Maximum Concentration of Toxic Gases, Dusts, and Vapors in the Air in Work Installations, Vol. 5, 7–15. Moscow: Indust. Hyg. & Occup. Dis. translated by courtesy of the United States Joint Publications Research Service, 1959, pp. 7–15.
4. Strafford, N., Strouts, C. R. N. and Stubbings, W. V., eds. 1956.The Determination of Toxic Substances in Air: A Manual of I.C.I. Practice, 134–136. Cambridge: W. Heffer & Sons, Ltd.
5. Elkins, H. B. 1959.The Chemistry of Industrial Toxicology, 2, 248–253. New York: John Wiley & Sons, Inc.