1. J. Whittall, 4n + 2 Systems: fulgides, in: Photochromism: Molecules and Systems (H. Durr and H. Bouas-Laurent, eds.), pp. 467–492, Elsevier, Amsterdam (1990).
2. J. Whittall, Fulgides and fulgimides—a promising class of photochromes for application, in: Applied Photochromic Polymer System (C. B. McArdle, ed.), pp. 80–120, New York (1991).
3. H. G. Heller, C. C. Elliot, K. Koh, S. Al-Shihry, and J. Whittall, The design and development of photochromic systems for commercial applications, Spec. Publ.-R. Soc. Chem., 125, 156–168 (1993).
4. H. Stobbe, A product of the action of light on diphenylfulgide and the polymerization of phenylpropiolic acid, Berichte, 40, 3372–3382 (1907).
5. W. S. Johnson and G. H. Daub, The Stobbe condensation, Organic Reactions, 6, Chap. 1, pp. 1–73, John Wiley & Sons, Inc., New York (1951).