Ogul, B. “On the Application of the Averaging Method to One Problem of Optimal Control With Unfixed Time”. Ukrains’kyi Matematychnyi Zhurnal 76, no. 10 (May 7, 2025): 1497–1504. Accessed December 5, 2025. https://umj.imath.kiev.ua/index.php/umj/article/view/8606.