00377    a2200145   4500020001800000082001500018100002000033245003300053250001200086260005400098300002500152650001300177650001700190650002400207  a9780763766221  a614.4bMER  aMerrill, Ray M.  aIntroduction to epidemiology  a5th ed.  aBostonbJones and bartlett publishersc2010g2010  axix,417p.billc25cm  aMedicine  aepidemiology  aPreventive medicine