%0 Journal Article %A William J. Floyd %A Steven P. Plotnick %T Symmetries of planar growth functions. %J Inventiones mathematicae %D 1988 %P 501-544 %V 93 %N 2 %I mathdoc %U http://geodesic.mathdoc.fr/item/IM_1988__93_2_143607/ %F IM_1988__93_2_143607