Coote, Stephen
Penguin Group, 1988
Buku Teks SO
Salzman, L.F.
Oxford University Press, 1955
Buku Teks SO
Lane-Poole, Stanley, 1854-1931
Methuen, 1968
Buku Teks SO
Stenton, Doris Mary
Penguin Books, 1952
Buku Teks SO
Stenton, Doris Mary
Penguin Books, 1951
Buku Teks SO