@article{SLC_2012-2013_68_a1,
     author = {Filippo Disanto},
     title = {Unbalanced {Subtrees} in {Binary} {Rooted} {Ordered} and {Un-ordered} {Trees}},
     journal = {S\'eminaire lotharingien de combinatoire},
     publisher = {mathdoc},
     volume = {68},
     year = {2012-2013},
     url = {http://geodesic.mathdoc.fr/item/SLC_2012-2013_68_a1/}
}