Bovenkerk, Bernice, author
Springer, 2012
eBooks
Frances, Bryan, author:
Polity Press, 2014
Buku Teks SO
Thomas G.M. Schalkhammer, editor
Birkhauser, 2002
Buku Teks
Sobti, R.C., author
CRC Press, Taylor & Francis Group, 2009
Buku Teks
edited by Martin Fransman, Gerd Junne and Annemieke Roobeek
Blackwell, 1995
Buku Teks