中国科学院数学与系统科学研究院期刊网
Metrizability is Preserved by Sequence-Covering and Closed Maps
Peng Fei YAN(1),Shou LIN(2),Sh
Acta Mathematica Sinica, Chinese Series . 2004, (1): 87 -90 .  DOI: 10.12386/A2004sxxb0012