006220000a22001930004500003000900000005001700009100002300026710006700049245011100116562003600227264004900263300000900312041000800321650001700329650003300346650001300379650001300392650002300405PH-MaWHO20241108112305.0  aRobertson Susan E.  aWorld Health Organization. Expanded Programme on Immunization.  aResearch and development within the Expanded Programme on Immunization : the first five years (1987-1991).  aWHO/EPI/GEN/93.10.--Unpublished  aGeneva : bWorld Health Organization,c1993.  a48p.  aeng  aImmunization  aCommunicable disease control  aResearch  aVaccines  aProgram evaluation