1. Zsigmondy .Colloids and the Ultra-microscope174–174. (invisibility of light-cone with small slit)
2. Burton . 1921.The Physical Properties of Colloidal Solutions105–105. 110
3. Burton . 1921.The Physical Properties of Colloidal Solutions48–48. 110
4. Burton .The Physical Properties of Colloidal Solutions122–122.
5. Burton . 1921.The Physical Properties of Colloidal Solutions76–76.