%0 Journal Article %A Rousseau, C. %T Local Bifurcation of Critical Periods in Vector Fields With Homogeneous Nonlinearities of the Third Degree %J Canadian mathematical bulletin %D 1993 %P 473-484 %V 36 %N 4 %U http://geodesic.mathdoc.fr/articles/10.4153/CMB-1993-063-7/ %R 10.4153/CMB-1993-063-7 %F 10_4153_CMB_1993_063_7