Gillespie, Sheena, author
Allyn and Bacon , 1994
Buku Teks
Schneider, Susan C., author
Prentice-Hall, 1997
Buku Teks
Helaine Selin
Springer Science, 2012
eBooks
edited by Chibueze C. Udeani ... [et al.]
Council for Research in Values and Philosophy,, 2006
Buku Teks
Harvard Business Review Press, 2016
Buku Teks