[1] Ceder J.: 
Some generalixaixons of metric spaces. Pacific J. Math. 11 (1961), 105-126. 
MR 0131860[2] Gao Z.: 
Characterizations of metrizable spaces in terms of g-function. Math. Japonica 33 (IMS), 851-858. 
MR 0975862 | 
Zbl 0672.54023[3] Heath R. W.: 
Screenability, pointwise paracompactness, and metrization of Moore spaces. Canad. J. Math. 16 (1964), 763-770. 
MR 0166760 | 
Zbl 0122.17401[4] Heath R. W., Hodel R. E.: 
Characterizations of $\sigma$-spaces. Fund. Math. 77 (1973), 271-275. 
MR 0321016 | 
Zbl 0258.54027[5] Nagata J.: 
Metrizability, generalized metric spaces and $g$-functions. Comment. Math. Univ. Carolinae 29 (1988), 715-722. 
MR 0982791 | 
Zbl 0686.54019[7] Yun Z.: 
On a question about metrizable spaces. Questions and Answers in General Topology 6 (1988), 181-183. 
MR 1045613 | 
Zbl 0661.54028[8] Yun Z.: 
Characterizations of metrizable, $\aleph$- and Lašnev spaces in terms of g-functions. Math. Japonica (to appear). 
MR 1049089 | 
Zbl 0696.54021