Newspapers and trade magazines are good resources for finding information on companies. A local newspaper would be interested in local companies while trade magazines would be interested in covering companies in that industry. While there are several databases that include digitized newspapers, not all newspapers are digitized and trade magazine are less likely to be digitized before the 1990's. It may be that microfiche or print sources are required.
Any full-text database with several years of coverage can be used for historical research depending on how far back the coverage goes. Some databases are only indexing are others include full-text (either text or as a digital image). The type of information that can be found in articles and advertisements includes:
Unlike newspapers where digitization projects are making papers more available, trade magazines are less widely available in a digitized format particularly before the advent of the Internet. Most databases are subscription/fee-based resources. Finding relevant articles in trade literature that is not full-text/digitized may depend on using indexing sources similar to Readers Guide to Periodical Literature. The index will provide citation information that is then used to retrieve the article in print volumes. Additionally, some magazines did their own indexing (usually on an annual basis) so utilize that if it is available. A few indexing sources are listed below.
Advertisements are also important and can yield useful information but finding them is more challenging. Searching the databases with digitized content will retrieve advertisements. However, text-based databases often don't include advertisements. To find advertisements in print editions of the trade magazines, use the publication's advertiser index (usually noted in the table of contents) for each issue if it is available.
None of these databases (either digitized images or full-text) include all newspapers or magazines, and all of them have other limitations that can include: limited time period covered limited title coverage, database search limits, or general limits on functionality.
Any full-text database can be used for historical research depending on how far back their coverage goes and what time frame someone is looking at, but the ones below have coverage that is specifically historical in nature.
Below are a few tips for searching databases. Many of these tips and notes are particularly important when searching those databases with digitized content because these databases don’t function quite the same way as purely text based databases do.
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.
Many of the trade literature sources are not necessarily going to be digitized and searchable. Historically, indexing services have been the traditional way to access many of the articles found in trade literature if the journal did not index itself. Included below are many of the standard and relevant indexing titles. While many of the below indexes are available in electronic format, the print versions may be more widely accessible.
The following materials link to fuller bibliographic information in the Library of Congress Online Catalog. Links to digital content are provided when available.