Tirino, Virginia, et al. “Valproic Acid and 5-Azacytidine Promote an Increase of Stemness Phenotype in Human Osteosarcomas”. Italian Journal of Anatomy and Embryology, vol. 121, no. 1, Oct. 2017, p. 48, https://oajournals.fupress.net/index.php/ijae/article/view/2186.