License, verbatimPD
The National Gallery of Art: open access image with no usage restrictions under the NGA's open access policy (openaccess=1 in the Gallery's published_images dataset).
Andrea Palladio (author). The First Book of Andrea Palladio's Architecture. Treating of the Five Orders; and What is most necessary in Building. Correctly drawn from his Original Work, publish'd by himself at Venice, Anno 1570. And accurately engraved by I. Ware., published 1742. National Gallery of Art, Washington.