Carlzon, Jan, author
Harper Collins Publishers, 1989
Buku Teks
Roebuck, Deborah Britt, author
Business Expert Press, 2012
Buku Teks
Schiller, Bradley R., author
Random House of Canada, 1980
Buku Teks
Schiller, Bradley R., author
McGraw-Hill , 1997
Buku Teks
Palan, Ronen, author
Pinter, 1999
Buku Teks