Elton, Lord
Imperial commonwealth
Collins, 1945
Buku Teks SO
Loewe, Michael
Imperial China
Frederick A. Preager, 1965
Buku Teks SO
Lavell, C.F.
Imperial England
Macmillan, 1919
Buku Teks SO
Hadas, Moses
Imperial Rome
Time-Life Books, 1965
Buku Teks SO
Mitchell, Richard H.
Censorship in imperial Japan
Princeton University Press, 1983
Buku Teks