Zuhri, Ahmad Hadra, Yudi Soeharyadi, and Jalina Widjaja. “On Conditions for Controllability and Local Regularity of A System of Differential Equations”. Journal of the Indonesian Mathematical Society 29, no. 2 (July 31, 2023): 259–270. Accessed November 23, 2024. https://jims-a.org/index.php/jimsa/article/view/1584.