Iranian Mathematical Society (IMS)Bulletin of the Iranian Mathematical Society1017-060X39620131215Bifurcation of limit cycles from a quadratic reversible center with the unbounded elliptic separatrix12231248enL. PengSchool of Mathematics and System Sciences, Beihang UniversityY. LeiSchool of Mathematics and System Sciences, Beihang University/The 24th Middle School of Beijing20110525