Bifurcation of closed orbits from a limit cycle in R 2 Vinicio Moauro — 1981 Rendiconti del Seminario Matematico della Università di Padova
The four positive vortices problem : regions of chaotic behavior and the non-integrability M. S. A. C. Castilla; Vinicio Moauro; Piero Negrini; Waldyr Muniz Oliva — 1993 Annales de l'I.H.P. Physique théorique