Editor by Seymour Melman
The American Academy of Arts and Science, 1962
Buku Teks
Edward, David V., author
Holt, Rinehart and Winston, 1969
Buku Teks
Bechhoefer, Bernhard G., author
Brookings Institution, 1961
Buku Teks
edited by Ernest W. Lefever
Frederick A. Praeger, 1962
Buku Teks
Altmann, Jurgen, author
Routledge, 2006
Buku Teks