1. Bertelson, R.C., Photochromism, Brown, G.H., Ed., New York: Wiley–Interscience, 1971, p. 49.
2. Barachevskii, V.A., Lashkov, G.I., and Tsekhomskii, V.A., Fotokhromizm i ego primenenie (Photochromism and Its Applications), Moscow: Khimiya, 1977.
3. Guglielmetti, R., Photochromism: Molecules and Systems, Durr, H. and Bouas-Laurent, H., Eds., Amsterdam: Elsevier, 1990, p. 314.
4. Atabekyan, L.S., Roitman, G.P., and Chibisov, A.K., Zh. Anal. Khim. 1982, vol. 37, no. 3, p. 389.
5. Atabekyan, L.S. and Chibisov, A.K., J. Photochem., 1986, vol. 34, no. 3, p. P. 323.