Ultrasound-Guided Superficial Versus Deep Continuous Serratus Anterior Plane Block in Patients Undergoing Thoracotomy for Lung Surgery: A Randomized Controlled Trial. - Raghupathy, R; Negi, Sunder Lal; Biswas, Indranil; Singh, Harkant; Mandal, Banashree; Gourav, Krishna Prasad; Sharma, Arun (Annals of Cardiac Anaesthesia, 2026)