450935.fig.007a
(a)
450935.fig.007b
(b)
450935.fig.007c
(c)
450935.fig.007d
(d)
Figure 7: Two coexisting attractors of model (3) with . The initial values from left to right are , respectively. (a-b) Periodic attractor with period 12; (c-d) periodic attractor with period 16. The other parameters are identical to those in Figure 4 and .