1. The Jugular Foramen
2. Gray H:Anatomy of the Human Body.Philadelphia, Lea & Febiger, 1930, pp 178, 191
3. Pernkopf E:Atlas of Topographical and Applied Human Anatomy, vol 1.Philadelphia, W B Saunders, 1963, p 63
4. Shapiro R, Janzen AH:The Normal Skull: A Roentgen Study.New York, Paul B Hoeber, 1960, pp 103–105
5. Toldt C:The Regions of the Human Body. Part I. Osteology.New York, Rebman, 1903, p 88