004760000a22001570004500003000900000005001700009020001800026110003000044245011800074264004900192300000900241041000800250650003300258650001100291650001600302PH-MaWHO20241108112331.0  a92-4-158012-7  aWorld Health Organization  aVaccination certificate requirements and health advice for international travel : situation as on 1 January 1987.  aGeneva : bWorld Health Organization,c1987.  a83p.  aeng  aCommunicable disease control  aTravel  aVaccination