71 pages
English language
Published May 21, 1973 by U.S. Dept. of Health, Education, and Welfare, Social Security Administration : for sale by the Supt. of Docs., U.S. Govt. Print. Off..
George Nelson: How to see. (1973, U.S. Dept. of Health, Education, and Welfare, Social Security Administration : for sale by the Supt. of Docs., U.S. Govt. Print. Off.)
Subjects
- Visual perception.