Coba jelasin Rujukan dari Cap dalam bahasa melayu dong

God's Regents on Earth: A Thousand Years of Byzantine Imperial Seals, from the Dumbarton Oaks Collection

UK National Archives on seals

Not All Online Authority Seals are Credible - Harvard's Ben Edelman says "Suppose users have seen a seal on dozens of sites that turn out to be legitimate. Dubious sites can present that same seal to encourage more users to buy, register, or download."

Signet ring article - Berganza, London: http://www.berganza.com/feature-signets__sealed_with_a_ring.html

http://db.pbw.kcl.ac.uk/jsp/browseseals.jsp (database of Byzantine Seal impressions from ''Prosopography of the Byzantine World project (PBW)

Photographic reproductions of medieval seals in the Lichtbildarchiv älterer Originalurkunden searchable via the verteillte Bildarchiv prometheus