1. Letter from Professor A.A. Miles, director, Lister Institute of Preventive Medicine, London, UK, to Dr A.M. Payne, medical officer, WHO HQ, 14 January 1959, File S2-133-1, Box 88, WHO/SEA.
2. ‘International Certificate of Vaccination or Revaccination Against Smallpox’, 23 December 1963, File 228, Box 048, WHO/SEA.
3. ‘Smallpox Research’, 29 November 1966, File 023, Box 2, WHO/SEA.
4. Stepan, op. cit. (note 19), 192–93.