Reasonable use of images in course papers, presentations, and graduate theses/dissertations is generally covered by fair use. Images should be used with critical commentary, and need to be identified and cited.
Use the following elements when identifying and citing an image, depending on the information you have available. It is your responsibility to do due diligence and document as much as possible about the image you are using:
Using images without asking for permission is permitted for nonprofit educational purposes under fair use. Images copied from other sources should not be used without permissions in publications or for commercial purposes.