2
by Chou, Roger, Helfand, Mark, Peterson, Kim, Dana, Tracy
Published 2006
Agency for Healthcare Research and Quality (US)

4
by Helfand, Mark
Published 2007
Oregon Health & Science University

6
by Chou, Roger, Helfand, Mark, Peterson, Kim, Dana, Tracy
Published 2006
Agency for Healthcare Research and Quality (US)

8
by Helfand, Mark
Published 2007
Oregon Health & Science University