Chandra, Prakash, author
Vikas Publishing House, 1982
Buku Teks
Holsti, Kalevi J., author
Prentice-Hall, 1977
Buku Teks
Caldwell, Lawrence T., author
McGraw-Hill, 1981
Buku Teks
Artikel Jurnal
edited by Thomas R. Dye, Brett W. Hawkins
Charles E. Merrill, 1967
Buku Teks