TY  - RPRT
TI  - Trifocals, fitting possibilities and problems.
AU  - H BERENHOLTZ
PY  - 1950
DO  - 10.1097/00006324-195012000-00002
UR  - https://pubmed.ncbi.nlm.nih.gov/14785917/
ID  - 14785917
ER  -