TY  - RPRT
TI  - High-pass spatial frequency letters as clinical optotypes.
AU  - B Howland
AU  - A Ginsburg
AU  - F Campbell
PY  - 1978
DO  - 10.1016/0042-6989(78)90036-6
UR  - https://pubmed.ncbi.nlm.nih.gov/706157/
ID  - 706157
ER  -