1. Part IV: , , , , , Liebigs Ann. 1995, 317–327, preceding paper.
2. Dissertation, University of Marburg, 1992.
3. Diploma Thesis, University of Marburg, 1993.
4. Recent Reviews on polymethine dyes: [4a] Methine Dyes and Pigments in Ullmann's Encyclopedia of Industrial Chemistry, 5th ed., VCH, Weinheim, 1990, vol. A16, p. 487–534.
5. [4b] – Color Chemistry, 2nd ed., VCH, Weinheim, 1991.