Mill, Robert Christie, author
RajaGrafindo Persada, 2000
Buku Teks
Czinkota, Michael R., author
The Dryden Press , 1996
Buku Teks
Wild, John J., author
Prentice-Hall, 2003
Buku Teks
Wormald, Avison, author
Pan Books, 1973
Buku Teks
Czinkota, Michael R., author
The Dryden Press, 1994
Buku Teks