There are many, literally hundreds of databases containing journal articles, conference papers, books, book chapters and other information sources. They can be found in Databases A-Z and on most Subject Guides on tabs titled "Finding Articles/Using Databases" and similar names.
The University of California and UCI have many publishing partners. As a result fulltext access is available to a growing number of journals. A list of the selective publishers and platforms follows and a full list is available noting the publisher and platform name and interfiled.
The UC did not renew its subscription to the Elsevier Journal package for 2019 going forward . This dictates that content from those journals be requested via ILL. Also selective content for which the UC does not have perpetual access must be requested. Delivery is free & fast but not immediate and requires planning for access for current content from journals such as Lancet, Lancet Oncology, Cancer Letters, Cancer Epidemiology, Gene and hundreds of others. Check ScienceDirect for access or use the Request function in databases to order articles, or find alternative sources. When searching pay special attention to the publisher. To request articles from 2019+, go to ScienceDirect, click on "Get Access", then on "SFX Context Sensitive Linking" and then on "InterLibrary Loan Request" and enter the 16 digit number on the lower left hand corner of your UCI Photo ID (if you do not have that you should contact email@example.com by eMail using your UCI eMail address and ask how you can obtain a bar code). Complete form with your eMail address and you will be sent a pdf of the article very shortly at no cost to you. Be selective and mindful of how much you order.