Murray Longmore [and others]
Oxford University press, 2014
Buku Teks
Spickett, Gavin
Oxford University Press, 1999
Buku Referensi
Wiley Blackwell, 2015
Buku Teks
edited by Daniel Bodansky, Jutta Brunnee and Ellen Hey
University of Oxford Press, 2008
Buku Teks
Goran Koch; Sven Poulsen
Wiley Blackwell, 2009
Buku Teks