1. Bose, D.M., Sen, S.N., Subbara. B.V., ‘A Concise History of Science In India’, 1971, p.15
2. Winternitz, M., ‘History if Indian Literature’, Delhi, 1972, p.175.
3. Gosh, A. ‘Indian Archaeology Review’, 1962-63, p.12
4. Wheelar, R.E.M, ‘The Indus Civillization’, 1946, p.56-57.
5. Ray. P., ‘History of Chemistry in Ancient and Medieval India’, 1956, p. 100-110.
6. Reinbold, Muller, ‘Die Medizine in Rigveda’, 1930, p.315-87.
7. Griffith,R.T.H., ‘The Texts of the White Yajureveda’, Benaras, 1957, p. 253.
8. Neogi, P., ‘Iron in Ancient India’, 1914, p.28-31.
9. Griffith, R.T.H., ‘The Hymns of the Artharvaveda Vol.1’, Benaras 1916 p. 234.
10. Read, Jhon, ‘Through Alchemy to Chemistry’, 1914, p.28-31..
11. Bhular, G, ‘The laws of Manu Vol. XXV’, Delhi, 1964, p.188.
12. Sharma, R.K, ‘Bhawandash, Charka Samhita Vol. II’, Varanasi, 1977, p.220-221.