中国科学院数学与系统科学研究院期刊网
A Class of Planar n-polynomial System with at Least [3/8n~2] Family Limit Cycles
Jing Xin BAI
Acta Mathematica Sinica, Chinese Series . 2000, (2): 245 -252 .  DOI: 10.12386/A2000sxxb0034