A nation of states : essays on the American federal system
edited by Robert A. Goldwin
Rand McNally, 1963
 Buku Teks SO
Ferguson, John H.
The American federal government
McGraw-Hill, 1981
 Buku Teks SO
Ferguson, John H.
The American federal goverment
McGraw-Hill, 1961
 Buku Teks SO
Proceedings of the 1983 convention of The American Academy of Advertising
edited by Donald W. Jugenheimer
Kansas American Academy of Advertising, 1983
 Buku Teks SO
Proceedings of the 1984 convention of The American Academy of Advertising
edited by Donald R. Glover
Nebraska American Academy of Advertising, 1984
 Buku Teks SO