TY  - RPRT
TI  - Study types and study issues in clinical medicine.
AU  - Michael Koller
AU  - Wilfried Lorenz
PY  - 2006
DO  - 10.1016/j.forsciint.2006.05.010
UR  - https://pubmed.ncbi.nlm.nih.gov/16806775/
ID  - 16806775
ER  -