In this paper, it is proved that for any positive integer K, ther a exists a planar n-polynomial system which has a series of big limit cycles, and the number of the big limit cycles is at least K. Furthermore, there are many small limit cycles between any of them.
Jing Xin BAI.
The Relative Locations of Limit Cycles of an (E_n) System.. Acta Mathematica Sinica, Chinese Series, 2004, 47(2): 337-342 https://doi.org/10.12386/A2004sxxb0043