1. Adler, D. 1968.Solid State Physics, Edited by: Seitz, F., Turnbull, D. and Ehrenreich, H. Vol. 21, 1New York: Academic Press.
2. Appel, J. 1968.Solid State Physics, Edited by: Seitz, F., Turnbull, D. and Ehrenreich, H. Vol. 21, 193New York: Academic Press.
3. Optical absorption of small polarons in semiconducting NiO and CoO in the near and far infra-red
4. Polarons in crystalline and non-crystalline materials