@article{10_4153_CJM_1981_001_6,
     author = {Wormald, Nicholas C.},
     title = {On the {Tumber} of {Planar} {Maps}},
     journal = {Canadian journal of mathematics},
     pages = {1--11},
     year = {1981},
     volume = {33},
     number = {1},
     doi = {10.4153/CJM-1981-001-6},
     url = {http://geodesic.mathdoc.fr/articles/10.4153/CJM-1981-001-6/}
}