This recent case from the Third Circuit Court of Appeals is very important to understanding the FDCPA (Fair Debt Collection Practices Act).
The full citation to the case is: Riccio v Sentry Credit, Inc. (3rd Cir. March 30, 2020). And the Google Scholar link is here: https://scholar.google.com/scholar_case?case=18158055043397526690&q=%22fair+debt+collection+practices+act%22&hl=en&scisbd=2&as_sdt=3,44
(If you are not familiar with Google Scholar — check out this video — Google Scholar is a fantastic free resource).