Huy, B. V., T. Q. Tùng, and L. V. . Đăng Giao. “DETERMINATION OF NICOTINE IN TOBACCO WORKER’S URINE USING LIQUID-LIQUID EXTRACTION AND GAS CHROMATOGRAPHY-MASS SPECTROMETRY (GC-MS)”. Hue University Journal of Science: Natural Science, vol. 126, no. 1A, July 2017, pp. 141-9, doi:10.26459/hueuni-jns.v126i1A.4329.