1. The vertebrate eye and its adaptive radiation;Walls;Optom. Vis. Sci.,1942
2. On the visual-cell pattern of a homalopsine snake;Underwood;J. Anat.,1966
3. A Contribution to the Classification of Snakes;Underwood,1967
4. The eye;Underwood,1970
5. The reptilian retina. I. A new concept of visual-cell evolution;Walls;Am. J. Ophthalmol.,1934