Figure 10From: Bogdanov–Takens bifurcation of a Holling IV prey–predator model with constant-effort harvesting(a) A local amplification diagram of an unstable limit cycle for \((\mu _{1},\mu _{2})=(0.01.0.009952)\) in region III. (b) Two unstable equilibria \(E_{1}^{*}\) and \(E_{2}^{*}\), and a stable focus \(E_{3}^{*}\) are surrounded by a stable limit cycleBack to article page