All of these specialized encyclopedias provide a general overview of a topic, as well as digging in rather deeply for topics that run more than 2 pages in length. These sources include reference notes and extensive bibliographies that help you to locate other source material that was authored by respected researchers.
Since all of these recommended encyclopedias are multi-volume sets, the first thing you need to do is locate the volume containing the SUBJECT INDEX for each particular encyclopedia (usually the last volume of each set). Then when you look up your topic you will probably find lots of main entries that look somewhat similar, as well as lots of INDENTED ENTRIES that are sub-topics that might be distributed throughout the multi-volume set.
Here is an example from one of these encyclopedias, looking at the SUBJECT INDEX for entries on COMPETITION (this is a two-page PDF).
In this case, if you only pulled the volume that carried entries starting with the letter "C", you would find less than 1/5th of all entries that actually discussed various aspects of Competition! Those other entries are scattered across sixteen of the volumes from this one encyclopedia!
The first 2 resources in this group are massive multi-volume sets, each of which runs over a dozen volumes. And each volume is about 900 pages thick!
These first two are the most important research encyclopedias for nearly every topic you might tackle under Economics as well as any angle of the Social Sciences.
They happen to have similar titles, but cover vastly different time spans:
Below are key reference books that provide a general overview of a topic or help identify synonyms, related terms, or basic data. These sources often include references and lists of further readings.