Herring, E. Pendleton
McGraw-Hill, 1936
Buku Teks
Schultze, Charles L.
The Brookings Institution, 1977
Buku Teks
Philip G. Schrag
Little,Brown and Company, 1974
Buku Teks
Gaedeke, Ralph M.
Canfield Press , 1972
Buku Teks
Kulick, Andreas
Cambridge University Press , 2012
Buku Teks