Bang, H.H., and V.N. Huy. “Some Spectral Formulas for Functions Generated by Differential and Integral Operators in Orlicz Spaces”. Carpathian Mathematical Publications 13, no. 2 (August 3, 2021): 326–339. Accessed April 25, 2024. https://journals.pnu.edu.ua/index.php/cmp/article/view/4153.