N. M. Al-Mukhaini, T. A. Ba-Omar, E. A. Eltayeb, and A. H. Al-Shehi, “Characterisation of Nicotine and Cancer-Enhancing Anions in the Common Smokeless Tobacco Afzal in Oman”, Sultan Qaboos Univ Med J, vol. 15, no. 4, pp. 469–476, Nov. 2015.