Khan, M. K. U. ., M. A. . Uddin, M. A. . Uddin, and W. R. . Rab. “Thoracic Segmental Spinal Anesthesia in Patient With Severe COPD in Open Cholecystectomy”. Central Medical College Journal, vol. 6, no. 2, June 2023, pp. 97-100, doi:10.3329/cemecj.v6i2.67075.