1. Katyal M. (1968) Talanta15: 95
2. Katyal M., Prakash S. (1977) Talanta24: 367
3. Nevskaya E. M., Nazarenko V. A. (1972) Zh. Analit. Khim.27: 1696
4. Schiller K., Thilo E. (1959) Z. Anorg. Allgem. Chem.8: 718
5. Velašević K., Radović Z., Djukanović A. (1979) Arch. Pharm. (Beograd)29: 239