  In this paper some aspects on the periodic solutions of the extended
Duffing-Van der Pol oscillator are discussed. Doing different rescaling of the
variables and parameters of the system associated to the extended Duffing-Van
der Pol oscillator we show that it can bifurcate one or three periodic
solutions from a 2-dimensional manifold filled by periodic solutions of the
referred system. For each rescaling we exhibit concrete values for which these
bounds are reached. Beyond that we characterize the stability of some periodic
solutions. Our approach is analytical and the results are obtained using
averaging theory and some algebraic techniques.
