@article{CMUC_1982__23_3_a10,
     author = {Berman, David M.},
     title = {A note on choosability in planar graphs},
     journal = {Commentationes Mathematicae Universitatis Carolinae},
     pages = {537--540},
     publisher = {mathdoc},
     volume = {23},
     number = {3},
     year = {1982},
     mrnumber = {677861},
     zbl = {0505.05029},
     language = {en},
     url = {http://geodesic.mathdoc.fr/item/CMUC_1982__23_3_a10/}
}