Basil Blackwell, 1959
Buku Teks
Grayling, A. C.
Blackwell Publishers, 1997
Buku Teks
edited by Witold Marciszewski
Martinus Nijhoff Publishers, 1981
Buku Referensi
Cambridge University Press, 1997
eBooks
Allwood, Jens
Cambridge University Press, 1995
Buku Teks