Tirino, V., F. Paino, V. Desiderio, L. Altucci, and G. Papaccio. “Characterization and Gene Expression of Cancer Stem Cells Grown As Sarcospheres from Human Primary Sarcomas”. Italian Journal of Anatomy and Embryology, vol. 116, no. 2, Nov. 2011, p. 185, https://oajournals.fupress.net/index.php/ijae/article/view/4759.