Freire, Maria do Carmo Matias, et al. “Socioeconomic Inequalities and Changes in Oral Health Behaviors Among Brazilian Adolescents from 2009 to 2012”. Revista De Saúde Pública, vol. 49, Jan. 2015, p. 50, https://doi.org/10.1590/S0034-8910.2015049005562.