1. P. Laszlo and P. Stang, Orgamc Spectroscopy, Principles and Applications, Harper and Row, New York (1971) p. 220.
2. K.C. Frisch and L.P. Rumao, Revs. Macromol. Chem. Marcel Dekker, Inc., New York (1971) p. 103.
3. A.E. Oberth and R.S. Bruenner, Propellants Manufacture, Hazards and Testing, Advances m Chemistry Series 88, American Chemical Society, Washington, DC (1969) p. 92.