1. Kesava MenonJ. Soc. Chem. Ind., 1910,28, 1430.
2. Rau and SimonsenIndian Forest Records, 1922,9, 95.
3. Bushell and HilditchJ. Soc. Chem. Ind., 1938,57, 48.
4. Kartha and MenonProc. Ind. Acad. Sci., 1943,A 17, 114.
5. Hilditch and MurthiJ. Soc. Chem. Ind., 1939,58, 310.