Galal M. Elmanfe, Suad K. Omar , Ahmad B. Eznien. “Determination of Nicotine in Libyan Smokers and Nonsmokers’ Urine Samples by Ultraviolet-Visible Spectrophotometry ”. Journal of Pure & Applied Sciences , vol. 19, no. 5, Oct. 2020, pp. 126-31, https://doi.org/10.51984/jopas.v19i5.826.