TY  - BOOK
AU  - Porter, Paul B.
CN  - Q11
CN  - Q11
CY  - New York :
DA  - 1962.
ID  - 62915
KW  - Visual discrimination.
KW  - Space perception.
PB  - New York Academy of Sciences,
PP  - New York :
PY  - 1962.
T1  - A general gradient theory of spatial vision /
TI  - A general gradient theory of spatial vision /
ER  -