Iancu, Bogdan
Springer, 2012
eBooks
Watson, Adam, author
Routledge , 1997
Buku Teks
Andrews, William G.
D.van Nostrand Company,Inc., 1968
Buku Teks
Petra Dobner, Martin Loughlin, editors
Oxford University Press, 2012
Buku Teks
Kagan, Shelly, author
Westview Press, 1997
Buku Teks