12. Taylor, N. W. "Foveal Vision: Dependence of Threshold
Energy on the Visual Angle of a Circular Target,"
J. Optic Soc. Am., 52, 7, 820-825, (July 1962).
13. Walls, G. L. "Factors in Human Visual Resolution,"
J. Optic. Soc. Am., 33, 9, 487-505, (1943).
14. Weymouth, F. W., D. C. Hines, L. H. Acres, J. E. Raaf,
M. C. Wheeler. "Visual Acuity within the Area
Centralis and its Relation to Eye Movements and
Fixation." Am. J. Ophthal., 11, 12, 947-960,
(Dec. 1928).