1. Kellman GM, Alpern MB, Sandler MA, Craig BM: CT of vena cava anomalies with embryologic correlation.Radiographics 8:533–556, 1988
2. Pollack HM:Clinical Urography. Philadelphia: W.B. Saunders, 1990, pp. 2076–2077, 2097–2104, 2112–2118
3. Streeter GL: Developmental horizons in human embryos. Description of age group XI, 13 to 20 somites, and age group XII, 21 to 29 somites.Carnegie Inst Wash Publ 541, Contrib Embryol 30:211–245, 1942
4. Streeter GL: Developmental horizons in human embryos. Description of age group XIV, embryos about 4 or 5 millimeters long, and age group XIV, period of indentation of the lens vesicle.Carnegie Inst Wash Publ 557, Contrib Embryol 31:27–63, 1945
5. Streeter GL: Developmental horizons in human embryos. Description of age groups XV, XVI, XVIII and XVIII, being the third issue of a survey of the Carnegie Collection.Carnegie Inst Wash Publ 575, Contrib Embryol 32:133–203, 1948