ZENKU, T. .; JOLEVSKA-TUNESKA, B. . Results on the Exponential Integral. Sarajevo Journal of Mathematics, [S. l.], v. 13, n. 1, p. 71–80, 2017. DOI: 10.5644/SJM.13.1.05. Disponível em: https://sjm.anubih.ba/index.php/sjm/article/view/104. Acesso em: 15 oct. 2024.