Existence of at Least Two Periodic Solutions for a Competition System of Plankton Allelopathy on Time Scales

Figure 1

Blue lines stand for 𝑥^∗1(𝑡), 𝑥^∗2(𝑡), red lines stand for 𝑥^1∗∗(𝑡),𝑥^2∗∗(𝑡).

(a)

(b)