@article{MZ_1968__108_171096,
     author = {Solomon Leader},
     title = {Extensions {Based} on {Proximity} and {Boundedness.}},
     journal = {Mathematische Zeitschrift},
     pages = {137--144},
     publisher = {mathdoc},
     volume = {108},
     year = {1968},
     zbl = {0169.54002},
     url = {http://geodesic.mathdoc.fr/item/MZ_1968__108_171096/}
}