Ali Taher, Mohammad. 2010. “Determination of Trace Amounts of Cobalt by Flame Atomic Absorption Spectrometry After Solid-Liquid Extraction and Preconcentration With Use of Nitroso-R Salt ”. Asian Journal of Chemistry 15 (3):1266-74. https://asianpubs.org/index.php/ajchem/article/view/21800.