Sources for photos and images in the public domain (free to use without permission).
flickr's The Commons
from the world's public photography archives
Under Search Tools, use the Usage Rights menu to narrow results to photos labeled for reuse.
Artist's last name, first name. Title of Work. Date or N.d. if no date. Name of institution that houses the work or name of private collection. City where institution or collection is located if available. Title of Website. Web. Date of access in the form of day month year.
Hamm, Frank. Manoa Falls. 19 May 2010. Flickr. Web. 2 Sept. 2015.
Bishop, Bernice Pauahi. Hawaii State Archives. Honolulu. N.d. Hawaii State Archives Digital Collections. Web. 19 June, 2018.
REMEMBER: If you cannot find the author, publisher, etc., for the online source, cite what is available. For further assistance, please ask a reference librarian.