中国科学院数学与系统科学研究院期刊网
An Extension of Frigon's Fixed Point Theorem and Its Simplifyied Proof
Xiao Yan LIU; Jin Xuan FANG
Acta Mathematica Sinica, Chinese Series . 2007, (5): 1087 -109 .  DOI: 10.12386/A2007sxxb0127