1. Organic photochromism (IUPAC technical report);Bouas-Laurent;Pure Appl Chem,2001
2. 4n+2 systems: spiropyrans;Guglielmetti,1990
3. 4n+2 systems: spirooxazines;Chu,1990
4. Spirooxazines;Maeda,1999
5. Benzo and naphthopyrans (Chromenes);Van Gemert,1999