1. F. Gutmann, L.E. Lyons: Organic Semiconductors (Wiley and Sons, New York 1967)
2. H. Meier: Organic Semiconductors (Verlag Chemie, Weinheim 1974)
3. N. Karl: “Organic Semiconductors. In Festkörperprobleme XIV, (Vieweg, Braunschweig 1974) p. 261
4. J. Ferraris, D.O. Cowan, V. Walatka, Jr., J. H. Perlstein: J. Am. Chem. Soc. 94, 670 (1973)
5. L. B. Coleman, M.J. Cohen, D. Sandman, F. G. Yamagishi, A. F. Garito, A.J. Heeger: Solid State Commun. 12, 1125 (1973)