CHEN, C.-M.; LIN, C.-J. Common fixed point theorems for contraction type mappings in partially ordered metric spaces. Tamkang Journal of Mathematics, [S. l.], v. 43, n. 1, p. 21–26, 2012. DOI: 10.5556/j.tkjm.43.2012.754. Disponível em: https://journals.math.tku.edu.tw/index.php/TKJM/article/view/754. Acesso em: 1 apr. 2026.