Ivanova I, Minev I, Petkova G. Colistin Combined with Ampicillin–Sulbactam versus Colistin Monotherapy for Carbapenem-Resistant Acinetobacter baumannii Ventilator-Associated Pneumonia: A Retrospective Comparative Non-Randomized Cohort Analysis of Microbiological Eradication and 30-Day. Arch Anesth & Crit Care. 2026;.