*T.Y. Li, and J.A. Yorke, Period Three Implies Chaos, American Mathematical Monthly 82, 985 (1975).https://en.wikipedia.org/wiki/American_Mathematical_Monthly | *T.Y. Li, and J.A. Yorke, Period Three Implies Chaos, American Mathematical Monthly 82, 985 (1975).https://en.wikipedia.org/wiki/American_Mathematical_Monthly |