@article{AM2_1974__11_136449,
     author = {Sidney Penner and Karl J. Schroeder},
     title = {Abstract {Characterizations} of {Continuous} {Functions.}},
     journal = {Aequationes mathematicae},
     pages = {121--127},
     publisher = {mathdoc},
     volume = {11},
     year = {1974},
     zbl = {0291.54006},
     url = {http://geodesic.mathdoc.fr/item/AM2_1974__11_136449/}
}