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

7
by Chou, Roger, Helfand, Mark, Peterson, Kim, Dana, Tracy
Published 2006
Agency for Healthcare Research and Quality (US)

12
by Helfand, Mark
Published 2007
Oregon Health & Science University

16
by Chou, Roger, Helfand, Mark, Peterson, Kim, Dana, Tracy
Published 2006
Agency for Healthcare Research and Quality (US)