TY  - RPRT
TI  - An educational note from Berkeley.
AU  - R D Freeman
AU  - T E Cohn
PY  - 1973
DO  - 10.1097/00006324-197302000-00008
UR  - https://pubmed.ncbi.nlm.nih.gov/4511862/
ID  - 4511862
ER  -