1. P.K. Jaiswal, K.L. Yadava: Talanta,17, 236 (1970)
2. J.H. Mendez, F.B. Reig, J.M. Catatayud, M.C.P. Marti: Afinidad,35, 345 (1978) (Span); Chem. Abstr.,90, 96930 k, (1979)
3. P. Jaya Prakash Rao, B. Sethuram, T. Navaneeth Rao: Indian J. Chem.,20A, 733 (1981)
4. G.L. Cohen, G. Atkinson: Inorg. Chem.,3, 1741 (1964)
5. F. Feigl: Spot Tests in Organic Analysis. Elsevier, Amsterdam 1966