1. Council on Competitiveness: Innovate America (National Innovation Initiative Report) (2004) (date accessed: 2007.07.19),
http://www.compete.org/pdf/NII_Interim_Report.pdf
2. Nishiyama, R., Takeuchi, H., Watanabe, H., Nasukawa, T., Maeda, J., Kuramochi, T., Hayashiguchi, E.: Technical Document Mining Method for Future Technology Projections. In: Proc. of JSAI 2007 (in japanese) (2007)
3. Murata, M., Kanamaru, T., Shirado, T., Isahara, H.: Using the K Nearest Neighbor Method and BM25 in the Patent Document Categorization Subtask at NTCIR-5. In: Proc. of NTCIR-5 Workshop Meeting (2005)
4. Kim, J.H., Huang, J.X., Jung, H.Y., Choi, K.S.: Patent Document Retrieval and Classification at KAIST. In: Proc. of NTCIR-5 Workshop Meeting (2005)
5. Lent, B., Agrawal, R., Srikant, R.: Discovering Trends in Text Databases. In: Proc. of KDD 1997, pp. 227–230 (1997)