SROYSANG, B. Inequalities for the Incomplete Exponential Integral Functions. Communications in Mathematics and Applications, [S. l.], v. 4, n. 2, p. 145–148, 2013. DOI: 10.26713/cma.v4i2.171. Disponível em: https://www.journals.rgnpublications.com/index.php/cma/article/view/171. Acesso em: 26 oct. 2025.