KAUR, K.; BHATIA, S. S.; RAM, B. Double trigonometric series with coefficients of bounded variation of higher order. Tamkang Journal of Mathematics, [S. l.], v. 35, n. 3, p. 267–280, 2004. DOI: 10.5556/j.tkjm.35.2004.208. Disponível em: https://journals.math.tku.edu.tw/index.php/TKJM/article/view/208. Acesso em: 29 mar. 2024.