These are databases the Library subscribes to that can be used for business research. Some are specific to business while others like newspapers, can be used for general research, as well as for business research by searching on business people, companies, industry developments, etc. Also, many of the news sources contain advertising which is searchable as well.
The subscription resources marked with a padlock are available to researchers on-site at the Library of Congress. If you are unable to visit the Library, you may be able to access these resources through your local public or academic library.