Hall, Kermit L., author
Oxford University Press, 1991
Buku Teks
Bailey, Thomas Andrew, 1902-1983, author
D.C. Heath, 1987
Buku Referensi
Benston, Kimberly W., author
Routledge, 2000
Buku Teks
Howard, John Tasker, author
Thomas Y. Crowell, 1946
Buku Teks
Dell Publishing, 1967
Buku Teks