Nicol, A. V., J. Y. S. N., and R. Colbran. “Pure Squamous Cell Carcinoma of the Gallbladder in a Patient With Perforated Calculus Cholecystitis”. International Surgery Journal, vol. 9, no. 2, Jan. 2022, pp. 476-9, doi:10.18203/2349-2902.isj20220345.