Sargent, Lyman Tower, author
The Dorsey Press, 1981
Buku Teks
Macridis, Roy C., author
Little, Brown, 1983
Buku Teks
Sargent, Lyman Tower, author
Wadsworth , 2009
Buku Teks
Fowler, Robert Booth, author
University Press of Kansas, 1991
Buku Teks
King, J. Charles
McGraw-Hill, 1973
Buku Teks