@article{MM2_1972__6_154095,
     author = {A.K. Dewdney},
     title = {The {Chromatic} {Number} of a {Class} of {Pseudo-2-Manifolds.}},
     journal = {Manuscripta mathematica},
     pages = {311--320},
     publisher = {mathdoc},
     volume = {6},
     year = {1972},
     zbl = {0229.05112},
     url = {http://geodesic.mathdoc.fr/item/MM2_1972__6_154095/}
}