1. Polyurethanes, Chemistry and Technology, Part I. Chemistry;Saunders,1962
2. The Chemistry and Technology of Isocyanates;Ulrich,1996
3. http://www.bhopal.org/
4. O’Connor, M. J. PCT Int. Appl. U.S. 5,370,908, 1994.
5. Polyurethanes: Chemistry, Technology and Application;Wirpsza,1993