1. Photoconductivity and Doping Effect by NdPc of Polyvinylcarbazole (PVK)
2. I. Akihiko, S. Shinichi, W. Kazamasa, Japanese Patent No. JP 04333852 (1992).
3. K. Eiji, I. Takaaki, R. Setsu, T. Kauru, K. Emi, K. Masayuki, Japanese Patent No. JP 08,44,091 (1996).
4. G.R.B. Leus, A.W.M. Persoon, C.T. Weijkamp, US Patent No. 5330865 (1994).