Aurboonyawat T, Pereira V, Krings T, Toulgoat F, Chiewvit P, Lasjaunias P. Patterns of the Cranial Venous System from the Comparative Anatomy inVertebrates. Part III. The Ventricular System and Comparative Anatomy of the Venous Outlet of Spinal Cord and Its Homology with the Five Brain Vesicles. Interv Neuroradiol. 2008 Jun 30; 14(2):125-36.