[1] Takahashi Y.Some Geometric Constants ofBanach Spaces–A Unified Approach. Proc Internat Symposium
on Banach and Function Spaces II. Kitakyushu, Japan: Yokohama Publishers, 2007: 191–220

[2] Yang C, Wang F. On a new geometric constant related to the von Neumann- Jordan constant. J Math Anal Appl, 2006, 324: 555–565

[3] Kato M, Maligranda L, Takahashi Y. On James and Jordan-von Neumann constants and the normal structure coeffcients of Banach spaces. Studia Math, 2001, 144: 275–295

[4] Alonso J, Llorens-Fuster E. Geometric mean and triangles inscribed in a semicircle in Banach spaces. J
Math Anal Appl, 2008, 340: 1271–1283

[5] Alonso J, Martin P. A counterexample to a conjecture of G Zbaganu about the Neumann-Jordan constant.
Rev Roumaine Math Pures Appl, 2006, 51: 135–141

[6] Bana′s J, Hajnosz A, Wedrychowicz S. On convexity and smoothness of Banach space. Comment Math
Univ Carolin, 1990, 31: 445–452

[7] Yang C, Li H. An inequality between Jordan-von Neumann constant and James constant. Appl Math Lett, 2010, 23: 277–281

[8] Jim′enez-Melado A, Llorens-Fuster E, Saejung S. The von Neumann-Jordan constant, weak orthogonality
and normal structure in Banach spaces. Proc Amer Math Soc, 2006, 134: 355–364

[9] Sims B. A class of spaces with weak normal structure. Bull Austral Math Soc, 1994, 50: 523–528

[10] Llorens-Fuster E. Zbaganu constant and normal structure. Fixed Point Theory, 2008, 9(1): 159–172

[11] Jim′enez-Melado A, Llorens-Fuster E. The fixed point property for some uniformly nonsquare Banach
spaces. Boll Unione Mat Ital, 1996, 10A(7): 587–595

[12] Takahashi Y, Kato M. A simple inequality for the von Neumann-Jordan and James constants of a Banach
space. J Math Anal Appl, 2009, 359: 602–609

[13] Bynum W L. Normal structure coeffcients for Banach spaces. Pacific J Math, 1980, 86: 427–436