Matsumoto, Akio, and Ferenc Szidarovszky. “An Elementary Study of a Class of Dynamic Systems With Two Time Delays”. CUBO, A Mathematical Journal 14, no. 3 (October 1, 2012): 103–113. Accessed October 12, 2025. https://cubo.ufro.cl/index.php/cubo/article/view/1334.