Graves 1934, p. 161: "Akaba was so strongly protected by the hills, elaborately fortified for miles back, that if a landing were attempted from the sea a small Turkish force could hold up a whole Allied division in the defiles." Graves, Robert (1934). Lawrence and the Arabs. London: Jonathan Cape – via Internet Archive (archive.org).
Maartens, Nicholas F.; Wills, Andrew D.; Adams, Christopher B.T. (1 January 2002). "Lawrence of Arabia, Sir Hugh Cairns, and the Origin of Motorcycle Helmets". Neurosurgery. 50 (1): 176–180. doi:10.1097/00006123-200201000-00026. PMID11844248. S2CID28233149.
Maartens, Nicholas F.; Wills, Andrew D.; Adams, Christopher B.T. (1 January 2002). "Lawrence of Arabia, Sir Hugh Cairns, and the Origin of Motorcycle Helmets". Neurosurgery. 50 (1): 176–180. doi:10.1097/00006123-200201000-00026. PMID11844248. S2CID28233149.
"Lawrence of Arabia". The Wireless Weekly: The Hundred per Cent Australian Radio Journal. Sydney: Wireless Press. 19 April 1941. Retrieved 8 February 2024 – via Trove.
Maartens, Nicholas F.; Wills, Andrew D.; Adams, Christopher B.T. (1 January 2002). "Lawrence of Arabia, Sir Hugh Cairns, and the Origin of Motorcycle Helmets". Neurosurgery. 50 (1): 176–180. doi:10.1097/00006123-200201000-00026. PMID11844248. S2CID28233149.