@article{SLC_2005-2007_55_a4,
     author = {Roland Bacher and Gilles Schaeffer},
     title = {On {Generating} {Series} of {Coloured} {Planar} {Trees}},
     journal = {S\'eminaire lotharingien de combinatoire},
     publisher = {mathdoc},
     volume = {55},
     year = {2005-2007},
     url = {http://geodesic.mathdoc.fr/item/SLC_2005-2007_55_a4/}
}