Anything that you have not created yourself needs to be cited so readers/reviewers know who the creator actually is.
Noodletools is a great resource to help you build citations for the multimedia content you use.
A citation generator and management tool.
LOGIN: click the Clever icon in NoodleTools
When you Google (or Bing) for images, Google is NOT the source of that image. Google and Bing are the TOOLS (called search engines) you used to find images from websites. When you cite an image from a Google search, you need to identify the website that Google found it on. Here's how to do that: