F. Ahmadi-Motamayel, P. Falsafi, M. T. Goodarzi, and J. Poorolajal, “Comparison of Salivary pH, Buffering Capacity and Alkaline Phosphatase in Smokers and Healthy Non-Smokers : Retrospective cohort study”, Sultan Qaboos Univ Med J, vol. 16, no. 3, pp. 317–321, Aug. 2016.