Subject headings are assigned to books/ebooks in the library's catalog.
A "Subject heading" search finds titles on that subject. You can use the filters to sort the results by date, full text online, etc. Here are a few headings of potential interest to get you started
Subject Subheadings - you can add to your subject search after the names of states, regions, and main subjects. For instance: California - economic conditions
Some subject headings use "economic" as an adjective For instance: Economic Geography
(Adapted from Duke University's Economics Research Guide)