@article{10_4153_CJM_1975_128_3,
     author = {Abernethy, Kenneth C.},
     title = {Characterization of {Certain} {Classes} of {Spaces} {With} {G\ensuremath{\delta}} {Points} as {Open} {Images} of {Metric} {Spaces}},
     journal = {Canadian journal of mathematics},
     pages = {1229--1238},
     year = {1975},
     volume = {27},
     number = {6},
     doi = {10.4153/CJM-1975-128-3},
     url = {http://geodesic.mathdoc.fr/articles/10.4153/CJM-1975-128-3/}
}