Harlow, Ralph Volney, author
Holt, Rinehart and Winston, 1961
Buku Teks
Buchanan, A. Russell, author
Harper & Row, Publishing, 1964
Buku Teks
Henry, Charles P., author
Fakultas Ilmu Sosial dan Ilmu Politik Universitas Indonesia, 2000
Artikel Jurnal
edited by Allan Nevins and Louis M. Hacker
D.C. Heath, 1943
Buku Teks
Rostow, Walt Whitman, author
A Clarion Book, 1969
Buku Teks