536570.fig.0011a
(a)
536570.fig.0011b
(b)
536570.fig.0011c
(c)
536570.fig.0011d
(d)
Figure 11: Bifurcation diagrams w.r.t. for different values of and for the following parameter values: , , , , and the initial condition ; (a) ; (b) , (c) , (d) .