1. Beckenbach, E.F.: Convex functions. Bull. Am. Math. Soc. 54, 439–460 (1948)
2. Bhatia, R., Davis, C.: A Cauchy–Schwarz inequality for operators with applications. Linear Algebra Appl. 223(224), 119–129 (1995)
3. Dannan, F.M.: Matrix and operator inequalities. J. Inequal. Pure Appl. Math. 2 (2001) (article 34)
4. Dragomir, S.S.: Hermite–Hadamards type inequalities for operator convex functions. Appl. Math. Comput. 218, 766–772 (2011)
5. Dragomir, S.S.: Some inequalities for trace class operators via a Kato’s result. RGMIA Res. Rep. Coll. 17 (2014) (preprint, article 105)