McCoubrey, Hilaire, author
Brookfield Dartmouth , 1995
Buku Teks
Nathan, James A
Little, Brown, 1983
Buku Teks
Westview Press, 1982
Buku Teks
American Assembly, Graduate School of Business, Columbia University, 1957
Buku Teks
Mayall, James B. L., author
Standard Publishers, 2009
Buku Teks