Williamson, John
Basic Books, Inc., 1983
Buku Teks
Flint, Colin, author
Pearson/Prentice Hall, 2007
Buku Teks
Flint, Colin, author
Taylor and Francis Group, 2018
Buku Teks
Freeman Cooper & Company, 1984
Buku Teks
Ohmae, Kenichi, author
Harper Business, 1999
Buku Teks