1. R. H. Friend, R. W. Gymer, A. B. Holmes, J. H. Burroughes, R. N. Marks, C. Taliani, D. D. C. Bradley, D. A. Dos Santos, J. L. Bredas, M. Lögdlund, and W. R. Salaneck, Nature (London) 397, 121 (1999).
2. Semiconducting Polymers: Chemistry, Physics, and Engineering, Ed. by G. Hadzüoannou and P. F. van Hutten (Wiley, Weinheim, Germany, 2000).
3. Yu. A. Gorokhovatskiĭ and G. A. Bordovskiĭ, Thermally Activation Current Spectroscopy of High-Resistance Semiconductors and Dielectrics (Nauka, Moscow, 1991) [in Russian].
4. P. G. Kasherininov and D. G. Matyukhin, Fiz. Tekh. Poluprovodn. (St. Petersburg) 32(6), 668 (1998) [Semiconductors 32 (6), 599 (1998)].
5. V. I. Arkhipov, E. V. Emelianova, R. Schmechel, and H. von Seggern, J. Non-Cryst. Solids 338–340, 626 (2004).