1. Anke, M., Angelow, L., Glei, M., et al., Fresenius J. Anal. Chem., 1995, vol. 352, no. 1, p. 92.
2. Wang, K., Nickel: Trace Elements in Life Science, Peking: Chinese Measurement, 1991.
3. Li, Y., Jiang, Y., and Yan, X.P., Talanta, 2004, vol. 64, no. 3, p. 758.
4. Teissedre, P.L., Cabrera Vique, C., Cabanis, M.T, et al., Am. J. Enol. Viticult., 1998, vol. 49, no. 2, p. 205.
5. Saavedra, Y., Gonzalez, A., Fernandez, P., et al., Spectrochim. Acta, B, 2004, vol. 59. no. 4, p. 533.