Academic and research libraries typically use Library of Congress Classification (LCC) to organize their print materials, which means books on the same subject should be next to or near each other on the shelf. This information can be used to find books in person or via the Library Catalog.
Example LCC call number ranges:
Example LCC subject headings:
*Use for the marketing of a particular product/service.
These reference materials are available online (click the link under View Online).
These websites are freely available online. No username or password necessary!