You must cite your source of information any time you use another person’s ideas, opinion or theory. You must also provide citations for any facts, statistics, graphs, or drawings that are not common knowledge. Quotations of another person's actual spoken or written word and paraphrases of another person's spoken or written words must also be cited.
Most Library Databases provide an option to create an account within the database to store and share your articles. Simply look for a login link and follow the instructions.
You can also download the ReadCube app from here: https://www.readcube.com or or download from your favorite App store.