P, Ingala, Lepira F, and Mputu L. 2017. “Validation of Irma Cgea Crenk One Method of Evaluation of the Vitamin D at the Regional Center of Nuclear Study Laboratory of Kinshasa”. American Scientific Research Journal for Engineering, Technology, and Sciences 38 (2): 59-67. https://asrjetsjournal.org/American_Scientific_Journal/article/view/3668.