Li, Yingehao, compiler
China Intercontinental Press, 2009
Buku Teks
Macmillan Press, 1978
Buku Teks
Koupelis, Theo, author
Jones & Bartlett learning, 2011
Buku Teks
Steinby, Torsten, author
Government, 1971
Buku Teks
Mangan, James T., author
Prentice-Hall, 1963
Buku Teks