Nurlybaev, I. and Imangalieva, B. 2011. About the formulation of the periodic law (PL) and periodic system of D.I. Mendeleev. Chemical Bulletin of Kazakh National University. 64, 4 (Dec. 2011), 173-175. DOI:https://doi.org/https://doi.org/10.15328/chemb_2011_4173-175.