APPLICATION OF THE SIX-SIGMA METHOD IN QUALITY CONTROL OF PERIPHERAL BLOOD CELL ANALYSIS ON THE DXH 690T MACHINE AT THE LABORATORY DEPARTMENT – VINMEC SMART CITY INTERNATIONAL GENERAL HOSPITAL. YHCĐ [Internet]. 2026 Mar. 2 [cited 2026 Nov. 9];67(2). Available from: https://tapchiyhcd.vn/index.php/yhcd/article/view/4347