Figure 6: (a) The black curve denotes an order-1 periodic solution to system (1), where the yellow curve denotes the trajectory in system (1) and the black symbol denotes the initial point, , , . (b) The region that comprises the red line, blue line, and black curve is an attractor in system (1), where the green curve denotes the trajectory of system (1) and the black symbol denotes the initial point, , , .