Beijing The National Commission of the People's Republic of China for Unesco 1989,
Buku Teks
Smith, Norman Kemp
The Modern Library, 1958
Buku Teks
Urmson, J.O., author
Clarendon Press, 1960
Buku Teks
Stumpf, Samuel Enoch, 1918-1998, author
McGraw-Hill, 1971
Buku Teks
Artikel Jurnal