Borkenau, Franz
Harper & Brothers , 1953
Buku Teks
Wilson, Edmund, 1895-1972, author
Doubleday & Co., 1972
Buku Teks
Borkenau, Franz
University of Michigan Press, 1962
Buku Teks
Turnock, David
Routledge, 1997
Buku Teks
Monnerot, Jules, author
George Allen and Unwin, 1953
Buku Teks