Spengler, Oswald, author
Alfred A. Knopp, 1947
Buku Teks
Luthfi Auni, author
McGill University Montreal, 1993
Buku Teks
Posner, Richard A., author
Harvard University Press, 2001
Buku Teks
Crotty, William J., author
Little, Brown, 1980
Buku Teks
Taylor, A.J.P. (Alan John Percivale), 1906-1990, author
Penguin Books in association with Hamish Hamilton, 1967
Buku Teks