Limit Cycles Bifurcated from a Reversible Quadratic Center
Jinming Li

In this paper, we consider the quadratic perturbations of the one parameter family of reversible quadratic system that write in the complex form as $$\dot{z}=-iz(1+a\bar{z})$$ being $a\ne0$ a complex number. We prove that the exact upper bound of the number of limit cycles produced by the period annulus system is two.