References

ORTHOGONALITY AND IN NORMED LINEAR SPACES


[1] G. C. Birkhoff, Orthogonality in linear metric space, Duke Math. J. 1 (1935), 169-172.

[2] J. Chmielinski, Remarks on orthogonality preserving mapping in normed spaces and some stability problems, Banach J. Math. Anal. 1 (1) (2007), 117-124.

[3] R. C. James, Orthogonality and linear functionals in normed linear spaces, Trans. Amer. Math. Soc. 61 (1947), 265-292.

[4] F. Mazaheri and F. M. Maalek Ghaini, Quasi-orthogonality of the best approximant sets, Nonlinear Analysis 65 (3) (2006), 534-537.

[5] H. Mazaheri and S. M. Vaezpour, Orthogonality and in Banach spaces, Aust. J. Math. Anal. Appl. 2(1) (2005), 1-5.

[6] I. Singer, Best Approximation in Normal Linear Spaces by Elements of Linear Subspaces, Springer, New York, 1970.

[7] A. Shoja and H. Maszaheri, General orthogonality in Banach spaces, Int. J. of Math. Analysis 1 (12) (2007), 553-556.