论文题目：Existence of Four-Intersection-Point Limit Cycles with Only Saddles Separated by Two Parallel Straight Lines in Planar Piecewise Linear Systems

期刊：International Journal of Bifurcation and Chaos(Vol. 33, No. 06, 2350071 (2023))

https://www.worldscientific.com/doi/10.1142/S0218127423500712