Question: What important information is missing from each of the following references?
a. Personal communication, 2016.
b. Business Week, p. 80.
c. Basic Business Communication (Burr Ridge, Ill.: Richard D. Irwin).
d. James A. White, "Will the Real S&P 500 Please Stand Up? Investment Firms Disagree on Index," Wall Street Journal.
e. Data were obtained from the White House Economic Statistics Briefing Room on the Internet.