SAHNEY, B. N. On the Borel Summability of Double Fourier Series. The Journal of the Indian Mathematical Society, [S. l.], v. 25, n. 3-4, p. 221–227, 1961. Disponível em: https://www.informaticsjournals.com/index.php/jims/article/view/22061. Acesso em: 29 apr. 2024.