Eckstein, H. W. (1991). Color in the 21st century: A practical guide for graphic designers, photographers, printers, separators, and anyone involved in color printing. Watson-Guptill.
Čikaški stil citiranja (17. izdanje)Eckstein, Helene W. Color in the 21st Century: A Practical Guide for Graphic Designers, Photographers, Printers, Separators, and Anyone Involved in Color Printing. New York: Watson-Guptill, 1991.
MLA način citiranja (9. izdanje)Eckstein, Helene W. Color in the 21st Century: A Practical Guide for Graphic Designers, Photographers, Printers, Separators, and Anyone Involved in Color Printing. Watson-Guptill, 1991.
Upozorenje: Ovi citati možda nisu uvijek 100% točni.