Hochwald, Werner
John Hopkins Press , 1969
Buku Teks
edited, Alberta M. Sbragia
Westview Press, 1983
Buku Teks
Pechman, Joseph A.
Harvester Wheatsheaf, 1989
Buku Teks
Fisher, Ronald C.
Routledge, 2016
Buku Teks
Maxwell, James A.
Brookings Institution, 1962
Buku Teks