Heater, Derek, author
Harvester Wheatsheaf, 1992
Buku Teks
edited by Linda Rae Bennett and Sharyn Graham Davies
Routledge, 2015
Buku Teks
Andreas Bandak
Brill, 2013
eBooks
New York Plenum Press 1991,
Buku Teks
Neumann, Victor, author
The Council for Research in Values and Philosophy , 2000
Buku Teks