1. Plotnikov, V.I., Kochetkov, V.L.: Zh. Anal. Khim., 23 (3), 377 (1968)
2. Lukovnikov, A.F., Ponomarev, A.N.: Radikokhimiya, 4, 19 (1962)
3. Lebedinskaya, M.P., Chuiko, V.T.: Zh. Anal. Khim., 28 (12), 2413 (1973)
4. Yamazaki, H., Gohda, S., Nishikawa, Y.: Bunseki Kagaku, 29, 58 (1980)
5. Chan, K.M., Riley, J.P.: Anal. Chim. Acta, 36, 220 (1966)