Alenka Selih
Springer, 2012
eBooks
East, Roger
Pinter Publishers, 1997
Buku Teks SO
edited by Andrew Blasko, Diana Januauskiene
Council for Research in Values and Philosophy, 2008
Buku Teks SO
Robbins, Peter T.
Springer, 2011
eBooks
Wilson, Peter H.
Routledge, 2000
Buku Teks SO