Columbia subject headings:
Business enterprises--United States--Mathematical models.
Industrial concentration--United States--Mathematical models.
Industrial organization (Economic theory)--Mathematical models.
Harvard subject headings:
Business enterprises--United States--Mathematical models.
Diversification in industry--United States.
Industrial concentration--United States--Mathematical models.
Industrial organization (Economic theory)--Mathematical models.
Input-output analysis.
Line of business reporting
Princeton subject headings:
Business enterprises.
Industrial organization.
Line of business reporting.