1. and Org. Magn. Reson. in press.
2. Chemistry of Synthetic Dyes, Vol. 1, Academic Press, New York (1952).
3. Azo and Diazo Chemistry, Wiley Interscience, New York (1961).
4. and in The Chemistry of Hydrazo, Azo and Azoxy Groups, Part 2, ed. by p. 838. Wiley, London (1975).
5. Azo Dye Tautomeric Structures Determined by Laser-Raman Spectroscopy