TY  - JOUR
AU  - Xiaoyi Tian
AU  - Qingxiang Xu
TI  - A note on extreme points in the closed unit ball of upper triangular 2 × 2 matrices over a C * -algebra
JO  - Filomat
PY  - 2022
SP  - 6767 
VL  - 36
IS  - 19
UR  - http://geodesic.mathdoc.fr/articles/10.2298/FIL2219767T/
DO  - 10.2298/FIL2219767T
LA  - en
ID  - 10_2298_FIL2219767T
ER  -