2
by Helfand, Mark
Published 2004
Agency for Healthcare Research and Quality (US)

3
by Chou, Roger, Clark, Elizabeth, Helfand, Mark
Published 2004
Agency for Healthcare Research and Quality

5
by Helfand, Mark
Published 2004
Agency for Healthcare Research and Quality (US)

6
by Helfand, Mark
Published 2009
Agency for Healthcare Research and Quality

7
by Chou, Roger, Clark, Elizabeth, Helfand, Mark
Published 2004
Agency for Healthcare Research and Quality