Gao , MuqileWu , Deyu and Chen , Alatancang. (2025). Generalized Estimation of Numerical Radius for the off-Diagonal 2×2 Operator Matrices and Its Application.
            <i>Journal of Mathematical Study</i>. <i>58</i> (3).
            323-337.
         doi:10.4208/jms.v58n3.25.05