Keegan, Warren J., author
Pearson, 2011
Buku Teks
Keegan, Warren J., author
Pearson Education , 2015
Buku Teks
Czinkota, Michael R., author
The Dryden Press, 1996
Buku Teks
Keegan, Warren J., author
Prentice-Hall, 2000
Buku Teks
Keegan, Warren J., author
Pearson , 2013
Buku Teks