1. M. Doriomedoff, F. Hautiere-Cristofini, R. de Surville, M. Jozefowicz, L. Yu et R.Buvet: J. Chem. Phys. 68, 39 (1971).
2. E.M. Genies, A.A. Syed and C. Tsintavis: Mol. Cryst. and Liquid Cryst., to be published
3. A.G. MacDiarmid, J. Chiang, M. Halpern, W.S. Mu, N.L.D. Somasiri, W. Wu and S.I. Yaniger: Mol. Cryst. and Liquid Cryst., to be published
4. T. Hjertberg, W.R. Salaneck, I. Lundström, N.L.D. Somasiri and A.G. MacDiarmid, unpublished
5. J.C. Evans, Spectroschimica Acta, 16, 428 (1960)