PATTERSON, R. F. Four dimensional characterization of bounded double sequences. Tamkang Journal of Mathematics, [S. l.], v. 35, n. 2, p. 129-134, 2004. DOI: 10.5556/j.tkjm.35.2004.214. DisponĂ­vel em: https://journals.math.tku.edu.tw/index.php/TKJM/article/view/214. Acesso em: 26 may. 2022.