BABU, G. V. R. Generalization of fixed point theorems relating to the diameter of orbits by using a control function. Tamkang Journal of Mathematics, [S. l.], v. 35, n. 2, p. 159-168, 2004. DOI: 10.5556/j.tkjm.35.2004.217. Disponível em: https://journals.math.tku.edu.tw/index.php/TKJM/article/view/217. Acesso em: 24 may. 2022.