Heltai, G., I. Fekete, G. Halász, K. Kovács, M. Horváth, A. Takács, N. Boros, and Z. Győri. “Multi-Elemental Inductively Coupled Plasma-Optical Emission Spectroscopic Calibration Problems of the Sequential Extraction Procedure for the Fractionation of the Heavy Metal Content from Aquatic Sediments”. Hungarian Journal of Industry and Chemistry, vol. 43, no. 1, June 2015, pp. 7-13, doi:10.1515/hjic-2015-0002.