1. Simons JH (1995) Fluorine chemistry, vol II. Academic, New York, p 38
2. Emeleus HJ (1995) Fluorine chemistry, vol I. Academic, New York, p 76
3. Lange W (1995) Fluorine chemistry, vol II. Academic, New York, p 12
4. Sony PL (1985) Textbook of inorganic chemistry. S. Chand, Delhi, p 425
5. Paul RC, Bhasin KK, Battu RS (1995) Fluorine chemistry. New age, New Delhi, p 33