DARJI, Kiran; VYAS, Rajendra. A note on double Fourier coefficients. Serdica Mathematical Journal, Sofia, Bulgaria, v. 46, n. 2, p. 101–108, 2020. Disponível em: https://serdica.math.bas.bg/index.php/serdica/article/view/190. Acesso em: 5 oct. 2026.