Anne Marie Coady, Sarah Bower, editors
Churchill Livingstone, 2015
Buku Teks
Baxi, Upendra, editor
Cambridge University Press, 2015
eBooks
Walker, Warren F., author
W.H. Freeman, 1974
Buku Teks
Polin, Richard A., author
Elsevier, Saunders, 2014
Buku Teks
Polin, Richard A., author
Elsevier Saunder, 2011
Buku Teks