1. Blanther JE (1892) Manufacture of contour relief maps. US Patent 473,901
2. Matsubara, K., “Molding method of casting using photocurable substance”, Japanese Kokai Patent Application, Sho 51[1976]-10813, 1974.
3. Sculpture exhibition School of the Art Institute of Chicago ( http://blogs.saic.edu/sugs/exhibitions/artifact/ )
4. Francois Willeme.: https://howlingpixel.com/wiki/Fran%C3%A7ois_Will%C3%A8me
5. Morioka I (1935) Process for manufacturing a relief by the aid of photography. US Patent 2,015,457