TY  - RPRT
TI  - Improving teaching Valsalva's maneuver.
AU  - F B Simmons
PY  - 1992
DO  - 10.1288/00005537-199208000-00022
UR  - https://pubmed.ncbi.nlm.nih.gov/1495362/
ID  - 1495362
ER  -