Dworkin, Ronald, author
Fontana Press, 1991
Buku Teks
Williams, Basil, author
Oxford University, 1945
Buku Klasik
Patalano, Alessio, author
UK Bloomsbury, 2015
Buku Teks
Young, Robert, 1950-, author
John Wiley & Sons, 2015
Buku Teks
Williamson, J.A.
Macmillan, 1965
Buku Teks