SAULIS, L. On an asymptotic expansion of independent randomly distributed multidimensional random variables sum density. Lithuanian Mathematical Journal, [S. l.], v. 11, n. 3, p. 651–663, 1971. DOI: 10.15388/LMJ.1971.21021. Disponível em: https://www.journals.vu.lt/LMJ/article/view/21021.. Acesso em: 4 may. 2024.