Salomons, Robert Paul, author
Adolf M. Hakkert, 1974
Buku Teks
Rijkens, Paul
Hottordam Unilever 1950,
Buku Teks
Salomons, Annie, author
C. A. J. Van dishoeck, 1920
Buku Teks
Meyer, Robert G., author
Allyn and Bacon, 1988
Buku Teks
Wayland, Robert E
Harvard Business School Press, 1997
Buku Teks