1. Duke-Elder S. and Cook C. Embryology. In: System of Ophthalmology Vol. III. Normal and Abnormal Development. S. Duke-Elder Ed. C. V. Mosby St. Louis 1963.
2. Mann I. The Development of the Human Eye. Grune and Stratton Inc. New York 1950.
3. The early development of the eye in stage human embryos;O'Rahilly R;Contrib. Embryol.,1966
4. Fine B. S. and Yanoff M. Ocular Histology a Text and Atlas. Harper and Row Hagerstown Md. 1979.
5. Illustrated Human Embryology, Vol. 3. Nervous System and Endocrine Glands. Springer-Verlag;Tuchmann-Duplessis H.;New York,1974