TY  - RPRT
TI  - Methacholine challenge tests: sample sizes required in crossover trials.
AU  - M Neuhäuser
AU  - K H Jöckel
PY  - 2006
DO  - 10.5414/cpp44027
UR  - https://pubmed.ncbi.nlm.nih.gov/16425968/
ID  - 16425968
ER  -