World Health Organization. Expert Committee on Smallpox. Meeting (1964 : Geneva, Switzerland)2012-06-172012-06-1719631963-12-31Smallpox/WP/6https://iris.who.int/handle/10665/67696Paper presented at the meeting of the Expert Committee on Smallpox, Geneva, 14-20 Janaury 1964Smallpox/WP/615 p.enSmallpoxVaccinationCommunicable Diseases and their ControlCertificat international de vaccination ou de revaccination contre la variole / document établi par le SecrétariatInternational certificate of vaccination or revaccination against smallpox / prepared by the Secretariatprevention and controllegislation