%0 Journal Article %A A. Gasull %A R. Prohens %T Effective computation of the first Lyapunov quantities for a planar differential equation %J Applicationes Mathematicae %D 1997 %P 243-250 %V 24 %N 3 %I mathdoc %U http://geodesic.mathdoc.fr/articles/10.4064/am-24-3-243-250/ %R 10.4064/am-24-3-243-250 %G en %F 10_4064_am_24_3_243_250