Lee Harrison, editor in chief
McGraw-Hill, 1995
Buku Referensi
Gray, Oscar S.
The Bureau of National Affairs, 1973
Buku Teks
Oppenheim, S. Chesterfield
Little, Brown , 1971
Buku Teks
edited by Shayne Cox Gad
Wiley-Interscience, 2008
Buku Teks
Malin, Martin H., author
Thomson/West, 2011
Buku Teks