Akhtar, M. S., Alam, P., Alvi, Y., Ali Rizvi, S. A., & Raza, M. H. (2019). A study of factors determining difficult surgery among patients undergoing laparoscopic cholecystectomy. International Surgery Journal, 6(9), 3322–3327. https://doi.org/10.18203/2349-2902.isj20194073