„Typhoid vaccines: WHO position paper”(PDF). Releve epidemiologique hebdomadaire / Section d'hygiene du Secretariat de la Societe des Nations = Weekly epidemiological record / Health Section of the Secretariat of the League of Nations. 83 (6): 49–59. . PMID18260212.
„Typhoid vaccines: WHO position paper”(PDF). Releve epidemiologique hebdomadaire / Section d'hygiene du Secretariat de la Societe des Nations = Weekly epidemiological record / Health Section of the Secretariat of the League of Nations. 83 (6): 49–59. . PMID18260212.