Lungu, Nicolae. “On Some Gronwall-Wendorff-Type Inequalities”. Rev. Anal. Numér. Théor. Approx. 22, no. 2 (August 1, 1993): 189–192. Accessed November 22, 2024. https://ictp.acad.ro/jnaat/journal/article/view/1993-vol22-no2-art8.