Porter, Michael E., author
The Free Press, 1985
Buku Teks
Porter, Michael E., author
Harvard Business Review Book, 1998
Buku Teks
Porter, Michael E., author
The Free Press , 1985
Buku Teks
Rothberg, Helen N, author
Elsevier Butterworth-Heinemann, 2005
Buku Teks
Harvard Business School Press, 1991
Buku Teks