358930.fig.008a
(a)
358930.fig.008b
(b)
358930.fig.008c
(c)
358930.fig.008d
(d)
358930.fig.008e
(e)
358930.fig.008f
(f)
Figure 8: Period-halving bifurcation leads to a -periodic solution of system (11): chaos and periodic solutions when , respectively.