TY  - RPRT
TI  - The private practice study group as phase-IV research tool.
AU  - H Helmchen
AU  - M Linden
AU  - G Schüssler
PY  - 1984
DO  - 10.1055/s-2007-1017429
UR  - https://pubmed.ncbi.nlm.nih.gov/6494245/
ID  - 6494245
ER  -