@article{bwmeta1.element.bwnjournal-article-fmv65i1p11bwm,
author = {J. Gresser},
title = {The range of a planar function with ambiguous points},
journal = {Fundamenta Mathematicae},
volume = {64},
year = {1969},
pages = {129-132},
zbl = {0206.28004},
language = {en},
url = {http://dml.mathdoc.fr/item/bwmeta1.element.bwnjournal-article-fmv65i1p11bwm}
}
Gresser, J. The range of a planar function with ambiguous points. Fundamenta Mathematicae, Tome 64 (1969) pp. 129-132. http://gdmltest.u-ga.fr/item/bwmeta1.element.bwnjournal-article-fmv65i1p11bwm/