Assertion: leech's use | /r/HasProperty | discussed by avicenna
Facets:
value: in the canon of medicine
type: LOCATION
value: in the 12th century.[citation
type: TEMPORAL
Source sentences:
text: Medical use of leeches was discussed by Avicenna in The Canon of Medicine (1020s), and by Abd-el-latif al-Baghdadi in the 12th century.[citation needed]