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.zurnalai.vu.lt/LMJ/article/view/20971. Acesso em: 8 jun. 2025.