"It is a free site that helps students find Creative Commons licensed images. The images that they download from Photos for Class come with attribution information embedded into the footer of the image."
"It is a free site that offers thousands of high quality images that you can download and re-use for free. PikWizard provides clear guidance on how you can use each picture that you find on the site. You will find that guidance posted to the right of any picture that you select from search results. PikWizard also provides clear directions on how to give credit to the photographers whose pictures you use."
Here you can download, share, and reuse millions of the Smithsonian’s images, access to more than 3 million 2D and 3D digital items from across the Smithsonian’s 19 museums, nine research centers, libraries, archives, and the National Zoo.