Roselino, Lourenço de Moraes Rego, et al. “Color Stability and Surface Roughness of Artificial Teeth Brushed With an Experimental Ricinus Communis Toothpast”. Brazilian Journal of Oral Sciences, vol. 14, no. 4, Sept. 2016, pp. 267-71, https://periodicos.sbu.unicamp.br/ojs/index.php/bjos/article/view/8646126.