Hoang Van Ly; Nguyen Huu Mai; Tran Van Hai; Ngo Nhat Tan; Dao Van Hoan; Nghiem Thi Hiep. INVESTIGATION OF FACTORS RELATING TO THE CHANGE OF CYCLE THRESHOLD (CT) INDEX IN RT-PCR TESTING AMONG COVID-19 PATIENTS, AT THE MILITARY HOSPITAL 7. TC YHQS 2023, 2-7.