1. Sediments in ink and in writing
2. Inks, Circular of the Bureau of Standards, Nr. 400, U.S. Dept. of Commerce.
3. and , Tinte, in Berl-Lunge, 4th vol., p. 4.
4. Beitrag zur kolloidehem. Technologic der Tinte, in R. E. Liesegang, Kolloidehemische Technologie, p. 404.