SZÁSZ, D.; FREYER, B. On the sums of a random number of random variables. Lithuanian Mathematical Journal, [S. l.], v. 11, n. 1, p. 181–187, 1971. DOI: 10.15388/LMJ.1971.20971. Disponível em: https://www.journals.vu.lt/LMJ/article/view/20971.. Acesso em: 29 apr. 2024.