A. Ghorbani, M. Rabbani, S. Waqif Husain, M. Mahmoodi, and M. Saberr-Tehrani, “Uncertainty Estimation for the Determination of Fe, Co and Ni in Natural Water Samples by SPE-ICP-OES”, ajc, vol. 22, no. 5, pp. 3871–3880, Mar. 2010.