Laski, Harold J.
George Allen and Unwin, 1946
Buku Teks
Brinton, Crane, 1898-1968
Prentice-Hall, 1952
Buku Teks
Laski, Harold J.
George Allen and Unwin, 1952
Buku Teks
Salvemini, Gaetano
W.W. Norton & Company, 1962
Buku Teks
Fitzgerald, C. P.
Cresset Press, 1953
Buku Teks