@article{JAC_2008__28_2_a4,
     author = {Zhao, Wenhua},
     title = {A noncommutative symmetric system over the {Grossman-Larson} {Hopf} algebra of labeled rooted trees},
     journal = {Journal of Algebraic Combinatorics},
     pages = {235--260},
     publisher = {mathdoc},
     volume = {28},
     number = {2},
     year = {2008},
     language = {en},
     url = {http://geodesic.mathdoc.fr/item/JAC_2008__28_2_a4/}
}