1. “Hazard Assessment of Ethylene Oxide”, C. R. C. Press Inc., 1986.
2. “Formaldehyde”, E. I. Dupont, de Nemours & Company Inc., Reinbold Publishing Corporation, Second Edition.
3. National Institute for Occupational Safety and Health, “Formaldehyde Air”, Anlytical Method No. P&CAM. 235, U. S. Department of Health, Cincinnati, Ohio, U.S.A., 1976.
4. National Institute for Occupational Safety and Health, “Formaldehyde Derivative Method No. S 327”, Department of Health Education and Welfare, Cincinnati, Ohio, U.S.A., 1977.