Brandt, Conrad, author
Harvard University Press, 1952, 1959
Buku Teks
Ebenstein, William, author
Prentice-Hall, 1954
Buku Teks
Hoover, J. Edgar (John Edgar), 1895-1972, author
Holt, 1958
Buku Teks
Bugajski, Janusz, author
Westview Press, 1991
Buku Teks
Brimmell, J. H.
Oxford University Press, 1959
Buku Teks