Ahadzadeh, A., Grigoryan, K., & Zhamharyan, H. (2012). DETERMINATION AND INVESTIGATION OF POLLUTION OF THE NIR RIVER IN ARDABIL PROVINCE OF IRAN. Proceedings of the YSU B: Chemical and Biological Sciences, 46(1 (227), 59–63. https://doi.org/10.46991/PYSU:B/2012.46.1.059