TY  - RPRT
TI  - Community-based research--a framework for problem formulation: the case of upper endoscopy for gastroesophageal reflux disease.
AU  - M Helfand
AU  - M A Oehlke
AU  - D A Lieberman
DO  - 10.1177/0272989x9701700308
UR  - https://pubmed.ncbi.nlm.nih.gov/9219192/
ID  - 9219192
ER  -