Great Britain. Public Record Office. (1968). Guide to seals in the Public Record Office. H.M.S.O..
Chicago-referens (17:e uppl.)Great Britain. Public Record Office. Guide to Seals in the Public Record Office. London: H.M.S.O., 1968.
MLA-referens (8:e uppl.)Great Britain. Public Record Office. Guide to Seals in the Public Record Office. H.M.S.O., 1968.
Varning: dessa hänvisningar är inte alltid fullständigt riktiga.