1. Photographic records of eye-movements in studying spelling.
2. Ahrens, A. Untersuchnngen ueber die Bewegung der Augen beim Schreiben. Rostock, 1891.
3. Anonymous. Movements of the Eyes in Beading. (Lancet, 1928),214, 664.
4. Anonymous. Rhythm reading: The ophthalm-o-graph, (devised by E. A. Taylor). (Chicago: The American Optical Company, 1935), pp. 35.