1. [1] W. Audeh, and F. Kittaneh, Singular value inequalities for compact op- erators, Linear Algebra Appl. 437(10) (2012), 2516-2522.
2. [2] T. Ando, Topics on operator inequalities. Sapporo: Division of Applied Mathematics, Research Institute of Applied Electricity, Hokkaido Univer- sity, (1978).
3. [3] R. Bhatia, and C. Davis, More operator versions of the Schwarz inequality, Comm. Math. Phys. 215(2) (2000), 239-244.
4. [4] R. Bhatia, Positive Deffnite Matrices, Princeton University Press, (2007).
5. [5] P.L. Čebyšev, O pribli_zennyh vyra_zenijah odnih integralov ćerez drugie, Soob_sćenija i protokoly zasedani_i Matemmatićeskogo obćestva pri Imper- atorskom Har'kovskom Universitete, No. 2, pp. 9398; Polnoe sobranie soćineni_i P. L. Čebyševa. Moskva Leningrad, 1948a, (1882), 128-131.