Robinson, Richard D.
The Dryden Press, 1978
Buku Teks
Globerman, Steven
Prentince-Hall, 1986
Buku Teks
Michael R. Czinkota, Ilkka A. Ronkainen, Michael H. Moffet, Eugene O. Moynihan
Harcourt College publishers, 2001
Buku Teks
Johnson, Debra
Routledge, Taylor & Francis group, 2003
Buku Teks
Ball, Donald A.
Business Publications, 1985
Buku Teks