Macridis, Roy C., author
Little, Brown, 1983
Buku Teks
Hagopain, Mark N.
Longman, 1978
Buku Teks
Fowler, Robert Booth, author
Praeger, 1985
Buku Teks
Sargent, Lyman Tower, author
Wadsorth Thompson Learning, 2003
Buku Teks
Abcarian, Gilbert
Charles Seribner's, 1970
Buku Teks