What they say about themselves:

Public

• advertising
• promotional materials
• press releases
• speeches
• books
• articles

Trade Professionals

• manuals
• technical papers
• licenses
• patents
• courses
• seminars

Government

• SEC reports
• FIC
• testimony
• lawsuits
• antitrust

Investors 

• annual meetings
• annual reports
• prospectuses
• stock/bond issues.

What others say about them:

Public

books

• articles
• case studies
• consultants
• newspaper reporters
• environmental groups
• consumer groups
• unions
• "who's who"
• recruiting firms

Trade professionals

• suppliers/vendors
• trade press
• industry study
• customers
• subcontractors

Government

• lawsuits
• antitrust
• state/federal agencies
• national plans
• government programs

Investors

• Security analyst reports
• industry studies
• credit reports