Elton, Lord
Imperial commonwealth
Collins, 1945
 Buku Teks
Hadas, Moses
Imperial Rome
Time-Life Books, 1965
 Buku Teks
Loewe, Michael
Imperial China
Frederick A. Preager, 1965
 Buku Teks SO
O`Connell, D. P.
Opinions on imperial constitutional law
The Law Book Company, 1971
 Buku Teks
Mitchell, Richard H.
Censorship in imperial Japan
Princeton University Press, 1983
 Buku Teks