Hossain, Muhammad Sazzad, et al. “A Comparison of Effectiveness F Betamethasone Gel and Lignocaine Jelly Applied to Tracheal Tube on Postoperative Sore Throat”. Faridpur Medical College Journal, vol. 13, no. 2, Oct. 2019, pp. 58-61, doi:10.3329/fmcj.v13i2.43621.