APA

Helfand M., Oehlke M. A. & Lieberman D. A. (19970904). Community-based research--a framework for problem formulation: the case of upper endoscopy for gastroesophageal reflux disease. : Medical decision making : an international journal of the Society for Medical Decision Making.

Chicago

Helfand M, Oehlke M A and Lieberman D A. 19970904. Community-based research--a framework for problem formulation: the case of upper endoscopy for gastroesophageal reflux disease. : Medical decision making : an international journal of the Society for Medical Decision Making.

Harvard

Helfand M., Oehlke M. A. and Lieberman D. A. (19970904). Community-based research--a framework for problem formulation: the case of upper endoscopy for gastroesophageal reflux disease. : Medical decision making : an international journal of the Society for Medical Decision Making.

MLA

Helfand M, Oehlke M A and Lieberman D A. Community-based research--a framework for problem formulation: the case of upper endoscopy for gastroesophageal reflux disease. : Medical decision making : an international journal of the Society for Medical Decision Making. 19970904.