Highlight, take notes, and otherwise mark up articles from quality sources. Whenever you quote or paraphrase any content, be sure to give credit to the authors.
References page example - the above source in APA style:
Rajsic, S., Breitkopf, R., Bachler, M., & Treml, B. (2021). Diagnostic Modalities in Critical Care: Point-of-Care Approach. Diagnostics (2075-4418), 11(12), 2202. https://doi.org/10.3390/diagnostics11122202
If you are looking for the specific type of article known as a case study, one easy way of finding the most useful articles is to include "case study" as one of your search terms. Note: this example limited the search to articles in which "case study" is the subject, for greater accuracy.