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.
a research tool that helps users collect and organize sources.
a free, open-source program that can be downloaded as a browser extension for Firefox, Chrome, and Safari and as a standalone program that works with Windows, Mac, or Linux systems.