[1] H. BRÉZIS F. BROWDER:
A general ordering principle in nonlinear functional analysis. Advances in Math. 21 (1976), 355-364.
MR 0425688
[2] F. BRØNSTED:
Fixed points and partial orders. Proc. Amer. Math. Soc. 60 (1978), 365-366.
MR 0417867
[3] J. CARISTI:
Fixed point theorems for mapping satisfying inwardness conditions. Trans. Amer. Math. Soc. 215 (1976), 241-251.
MR 0394329
[4] I. EKELAND:
Nonconvex minimization problems. Bull. Amer. Math. Soc. (New Series) 1 (1979), 443-474.
MR 0526967 |
Zbl 0441.49011
[5] B. FUCHSTEINER: Iterations and fixed points. Pacific J. Math. 68 (1977), 73-79.