It looks like you're using Internet Explorer 11 or older. This website works best with modern browsers such as the latest versions of Chrome, Firefox, Safari, and Edge. If you continue with this browser, you may see unexpected results.
If you're using citations from databases, the library catalog or citation generators, make sure you check your citations to see that they are in the correct format.
Citation managers like Zotero and Mendeley can help you keep track of the sources you gather for your assignment. You can add PDF copies of articles, links to websites. They also can help to formulate citations.