Kooij, Robert E.; Zegeling, André Co-existence of a period annulus and a limit cycle in a class of predator-prey models with group defense. (English) Zbl 1478.34059 Int. J. Bifurcation Chaos Appl. Sci. Eng. 31, No. 10, Article ID 2150154, 11 p. (2021). MSC: 34C60 34C05 34C23 92D25 34C25 × Cite Format Result Cite Review PDF Full Text: DOI
Dumortier, Freddy; Kooij, Robert E.; Li, Chengzhi Cubic Liénard equations with quadratic damping having two antisaddles. (English) Zbl 1025.34029 Qual. Theory Dyn. Syst. 1, No. 2, 163-209 (2000). Reviewer: Armengol Gasull (Bellaterra) MSC: 34C07 37C10 34C25 × Cite Format Result Cite Review PDF Full Text: DOI
Kooij, Robert E.; Sun, Jianhua A note on “Uniqueness of limit cycles in a Liénard-type system”. (English) Zbl 0872.34012 J. Math. Anal. Appl. 208, No. 1, 260-276 (1997). MSC: 34C05 34C25 × Cite Format Result Cite Review PDF Full Text: DOI Link