[1] M. Baronti, E. Casini and P. L. Papini, Triangles inscribed in a
semicircle, in Minkowski planes, and in normed spaces, J. Math. Anal.
Appl. 252 (2000), 124-146.
[2] M. M. Day, Some characterizations of inner product spaces, Trans.
Amer. Math. Soc. 62 (1947), 320-337.
[3] S. Dhompongsa, P. Piraisangjun and S. Saejung, Generalized
Jordan-von Neumann constants and uniform normal structure, Bull.
Austral. Math. Soc. 67 (2003), 225-240.
[4] S. Dhompongsa, A. Kaewkhao and S. Tasena, On a generalized James
constant, J. Math. Anal. Appl. 285 (2003), 419-435.
[5] T. Figiel, On the moduli of convexity and smoothness, Studia Math.
56 (1976), 121-155.
[6] J. Gao and K. S. Lau, On two classes of Banach spaces with uniform
normal structure, Studia Math. 99 (1991), 41-56.
[7] J. Gao, Modulus of convexity in Banach spaces, J. Appl. Math.
Lett. 16 (2003), 273-278.
[8] J. Garcia-Falset and B. Sims, Property (M) and the weak
fixed point property, Proc. Amer. Math. Soc. 125 (1997), 2891-2896.
[9] J. Garcia-Falset, The fixed point property in Banach spaces with
NUS-property, J. Math. Anal. Appl. 215 (1997), 532-542.
[10] B. Sims, A class of spaces with weak normal structure, Bull.
Austral. Math. Soc. 49 (1994), 523-528.
[11] C. Yang and F. Wang, On a generality modulus of convexity,
Journal of Henan Normal University 3(1) (2006), 55.