TY  - RPRT
TI  - First premolar or second premolar extractions: formula or clinical judgment?
AU  - D H Ketterhagen
PY  - 1979
DO  - 10.1043/0003-3219(1979)049<0190:fpospe>2.0.co;2
UR  - https://pubmed.ncbi.nlm.nih.gov/290284/
ID  - 290284
ER  -