The Congressional Research Service (CRS) is a division of the Library of Congress. They produce analytical, non-partisan reports on topics of interest to members of Congress. In 2018 they stood up a public website for dissemination of their more recent reports, and there are a number of free and subscription sites where you can find current and older CRS reports. You can also request copies from your Congressional Representative.
Many CRS reports are frequently updated, so try to find the most recent version using the resources in this guide. The CRS logo and a header from a typical CRS report are below.