Iranian Mathematical Society (IMS) Bulletin of the Iranian Mathematical Society 1017-060X 37 No. 2 2011 07 15 LINEAR ESTIMATE OF THE NUMBER OF ZEROS OF ABELIAN INTEGRALS FOR A KIND OF QUINTIC HAMILTONIANS101 116 en N. NYAMORADI H. ZANGENEH 2008 10 03 Zeros of Abelian integrals Hilbert's 16th problem limit cycles