Boswell, Richard A.
Carolina Academic Press, 1992
Buku Teks
Bruce, J. Campbell
Random House , 1954
Buku Teks
Jones, Maldwyn Allen
University of Chicago Press , 1960
Buku Teks
Maideus, Melinda
Facts on File, 1981
Buku Teks
Facts on file, 1981
Buku Teks