ZAGEL, H. Single mothers’ contact frequency with family and non-family members. Journal of Family Research, [S. l.], v. 32, n. 1, p. 25–44, 2020. DOI: 10.20377/jfr-156. Disponível em: https://ubp.uni-bamberg.de/jfr/index.php/jfr/article/view/156. Acesso em: 4 dec. 2022.