Laski, Harold J.
George Allen and Unwin, 1935
Buku Teks
Laski, Harold J.
George Allen and Unwin, 1956
Buku Teks
Harvard Business School Press, 1991
Buku Teks
Dodd, Walter Fairleigh, 1880-1960
Century, 1923
Buku Teks
Denisov, A.
Foriegn Language, 1960
Buku Teks