Artikel Jurnal
Howell, Signe, author
Berghahn Books, 2006
Buku Teks
Damisch, Hubert
MIT Press, 2000
Buku Teks
Sarabjot Singh, author
Management, Faculty of Economics, University of Indonesia and Philip Kotler Center, 2013
Artikel Jurnal
Schaarwachter, George, author
Erlangga, 1991
Buku Teks