@article{10_4153_CJM_1967_010_x,
     author = {Mullin, R. C.},
     title = {On the {Enumeration} of {Tree-Rooted} {Maps}},
     journal = {Canadian journal of mathematics},
     pages = {174--183},
     year = {1967},
     volume = {19},
     number = {1},
     doi = {10.4153/CJM-1967-010-x},
     url = {http://geodesic.mathdoc.fr/articles/10.4153/CJM-1967-010-x/}
}