008510000a22002770004500003000900000005001700009020001500026100002700041264004900068700001600117700002600133700002200159700002400181700001700205700002100222700002100243710003100264245012300295300001000418490003400428041000800462650003900470650003300509650002000542040001100562PH-MaWHO20241108112051.0 a9241400528 aPollock, Thomas Millar aGeneva : bWorld Health Organization,c1966. aBell, J. A. aBradford Hill, Austin aCockburn, W. Chas aCvjetanovic, Branko aEvans, D. G. aKostrzewski, Jan aSchofield, F. D. aWorld Health Organization. aTrials of prophylactic agents for the control of communicable diseases : a guide to their organization and evaluation. a92 p. aWHO monograph series ; no. 52 aeng aVaccinesxAdministration and usage aCommunicable disease control aClinical trials aWHOLIS