1. Bely, N., Borillo, A., Virbel, J. and Siot-Decauville, N. (1970) Procédures d’analyse sémantique appliquées a la documentation scientifique. Paris: Gauthier-Villars.
2. Biebricher, B. et al. (1988) The automatic indexing system AIR PHYS - from research to application. Proceedings of the 11th International Conference on Research and Development in Information Retrieval (ACM SIGIR.), pp. 333–342.
3. Buckley, C., Allan, J. and Salton, G. (1995) Automatic routing and retrieval using SMART: TREC-2. Information Processing and Management. 31 (3), pp. 315–326.
4. Callan, J., Croft, W.B. and Broglio, J. (1995) TREC and TIPSTER Experiments with INQUERY. Information Processing and Management, 31 (3), pp. 385–395.
5. Chan, L.M., Richmond, P.A. and Svenonius, E. (Eds.) (1985) Theory of subject analysis: a sourcebook. Littleton, CO: Libraries Unlimited.