Lama, Gina, et al. “Angiogenic Marker Expression in Cancer Stem Cells Derived from Glioblastoma and Peritumor Tissue”. Italian Journal of Anatomy and Embryology, vol. 117, no. 2, Feb. 2013, p. 93, https://oajournals.fupress.net/index.php/ijae/article/view/4279.