1. Hurlimann, H. and Cherbuliez, E. 1985.Karrer Konstitution und Verkommen der Organischen Pflanzenstoffe (Exklusive Alkaloids), Erganzungsband 2, Vol. Band 28, 1778–1796. Birkhauser Verlag. Teil 2 See also previous volumes 25, 17 and 12 in this series
2. Hattori and Dyes, M. 1993.Anthraquinones; Kirk-Othmer Encyclopedia of Chemical Technology,, 4th ed, Vol. 8, 602–671. J. Wiley & Sons, Inc.