Vincent, Andrew
Basil Blackwell, 1987
Buku Teks
Harvard Business School Press, 1991
Buku Teks
Dodd, Walter Fairleigh, 1880-1960, author
Century, 1923
Buku Teks
Denisov, A., author
Foriegn Language, 1960
Buku Teks
edited by Don K. Price
Prentice-Hall, 1960
Buku Teks