Husband, William H., author
Richard D. Irwin, 1948, 1955, 1962
Buku Teks
Epstein, Edwin M., author
Prentice-Hall, 1969
Buku Teks
Seoul The Corporation 1974,
Buku Teks
Masson, Robert L., author
McGraw-Hill, 1935
Buku Teks
Gordon, Robert Aaron, author
The Brookings Institution, 1945
Buku Teks