History of the Disposable Baby Diaper
- Overview of the history of baby diapers in ancient cultures, and the development of the modern disposable versions. Author: Carlos Richer.
- http://www.disposablediapers.com/ingles/html/homeing.html

Color Museum
- Information resource on color order systems in art and science. Illustrated color theories from Antiquity to modern times. The significance of colors in cultural systems. Interactive journey through Philip Otto Runge's color sphere. Chronological bibliogr
- http://www.colorsystem.com/