Mitchell, David A., author
Oxford University Press, 2014
Buku Referensi
Spickett, Gavin
Oxford University Press, 1999
Buku Referensi
Murray Longmore [and others]
Oxford University press, 2014
Buku Teks
Wiley Blackwell, 2015
Buku Teks
edited by Daniel Bodansky, Jutta Brunnee and Ellen Hey
University of Oxford Press, 2008
Buku Teks