@article{10_37236_1152,
     author = {Stephan G. Wagner},
     title = {On an identity for the cycle indices of rooted tree automorphism groups},
     journal = {The electronic journal of combinatorics},
     year = {2006},
     volume = {13},
     doi = {10.37236/1152},
     zbl = {1113.05050},
     url = {http://geodesic.mathdoc.fr/articles/10.37236/1152/}
}