引用本文:

严冬梅，田 云. 一类Lienard系统的Hopf环形数[J]. 浙江大学学报（理学版）, 2011, 38(1): 10-018.

YAN Dong-Mei, TIAN Yun. . Journal of ZheJIang University(Science Edition), 2011, 38(1): 10-018.

链接本文:

https://www.zjujournals.com/sci/CN/    或    https://www.zjujournals.com/sci/CN/Y2011/V38/I1/10