Image scanned from a book reproduced in a paper:
Fig. 1. Palermo Exhibiton. February 6-March 1 1968, archive of Galerie Konrad Fischer, Dusseldorf. From: Blinky Palermo: Abstraction of an Era. New Haven: Yale University Press, 2008. Figure 41.
Image downloaded from ARTstor reproduced in a paper:
Fig. 2. Frank Lloyd Wright, Frederick C. Robie House. 1906-1909, Architectural Model, 23.2 x 125.3 x 54.3 cm. The Museum of Modern Art, Architecture and Design Collection, New York, New York. Available from: ARTstor, http://www.artstor.org (accessed September 18, 2018).
Image downloaded from museum website reproduced in a paper:
Fig. 3. Caravaggio, The Denial of Saint Peter. Early 15th century. Oil on canvas, 94 x 125.4 cm. The Metropolitan Museum of Art, New York. From: The Metropolitan Museum of Art, http://www.metmuseum.org (accessed September 20, 2018)
Image downloaded from Flickr Commons reproduced in a paper:
Fig. 4. Thomas Eakins, William Rudolf O'Donovan. 1981, Black and white photographic print, 6 x 8 cm. Archives of American Art, Smithsonian Institution, Washington, DC. Available from: Flickr Commons, http://www.flickr.com/photos/smithsonian/2547841439 (accessed September 19, 2018.