Heltai, G., Fekete, I., Halász, G., Kovács, K., Horváth, M., Takács, A., Boros, N. and Győri, Z. 2015. 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. 43, 1 (Jun. 2015), 7–13. DOI:https://doi.org/10.1515/hjic-2015-0002.