Heller, Walter W., editor
[publisher not identified], 1974?
Buku Teks
Staley, Eugene
Published for the Council on Foreign Relations by Harper, 1961
Buku Teks
Artikel Jurnal
Weil, David N.
Pearsons Addison-Wesley, 2009
Buku Teks
Herrick, Bruce H.
McGraw-Hill, 1983
Buku Teks