20. CHANGES IN PLASMA MATRIX METALLOPROTEINASE-9 CONCENTRATIONS IN PATIENTS WITH CHRONIC OBSTRUCTIVE PULMONARY DISEASE IN AND OUT OF EXACERBATION AT MILITARY HOSPITAL 103 IN 2023. (2024). Vietnam Journal of Community Medicine, 65(CĐ 3 - Bệnh viện Phổi Trung ương). https://doi.org/10.52163/yhc.v65iCD3.1116