AMER, Mohammad Mahmud. ([On Summability Of Double Fourier Series And It’s Conjugate By Double Nörlund in The Space L_2 ([0,π]×[0,π . Journal of natural sciences, life and applied sciences, New Mexico, United States, v. 3, n. 3, p. 84–71, 2019. DOI: 10.26389/AJSRP.M030319. Disponível em: https://ajsrp.ojsexpert.com/index.php/jnslas/article/view/1742. Acesso em: 20 dec. 2025.