TY  - RPRT
TI  - A hand optometer for measuring dark focus.
AU  - W Jaschinski-Kruza
PY  - 1988
DO  - 10.1016/0042-6989(88)90043-0
UR  - https://pubmed.ncbi.nlm.nih.gov/3253997/
ID  - 3253997
ER  -