René Grousset (1970).
Cited in
- 2026-05-29-note-01 — The 626 Avar-Sasanian siege of Constantinople and the role of the Byzantine fleet (2026-05-29)
- 2026-05-30-note-01 — connection/relations between the Avars and Göktürks (2026-05-30)
René Grousset (1970).