X. Li, B. Liu, и S. Ng. Proceedings of the 2010 Conference on Empirical Methods in Natural Language Processing, стр. 218--228. Stroudsburg, PA, USA, Association for Computational Linguistics, (2010)
B. Lauser, и A. Hotho. Proc. of the 7th European Conference in Research and Advanced Technology for Digital Libraries, ECDL 2003, том 2769 из LNCS, стр. 140-151. Springer, (2003)