@article{DMGT_1996_16_2_a3,
     author = {Hor\v{n}\'ak, Mirko and Jendrol, Stanislav},
     title = {Unavoidable set of face types for planar maps},
     journal = {Discussiones Mathematicae. Graph Theory},
     pages = {123--141},
     publisher = {mathdoc},
     volume = {16},
     number = {2},
     year = {1996},
     language = {en},
     url = {http://geodesic.mathdoc.fr/item/DMGT_1996_16_2_a3/}
}