Hecker, Justus Friedrich Carl; Babington, Benjamin Guy (1859). The epidemics of the middle ages (بالإنجليزية). London: Trübner & co. pp. 202–205. Archived from the original on 2020-12-04.
Hecker, Justus Friedrich Carl; Babington, Benjamin Guy (1859). The epidemics of the middle ages (بالإنجليزية). London: Trübner & co. pp. 202–205. Archived from the original on 2020-12-04.