RAO, K. M. Quasi-Martingales. MATHEMATICA SCANDINAVICA, [S. l.], v. 24, p. 79–92, 1969. DOI: 10.7146/math.scand.a-10921. Disponível em: https://www.mscand.dk/article/view/10921. Acesso em: 2 may. 2024.