1. Alter, S.L.: Decision Support Systems: Current Practice and Contributing Challenge. Addison-Wesley, Reading (1990)
2. Bosc, P., Dubois, D., Pivert, O., Prade, H., de Calmes, M.: Fuzzy summarization of data using fuzzy cardinalities. In: Proc. 7th Internat. Conf. IPMU (IPMU 2002), Annecy, France,, pp. 1553–1559 (2002)
3. Checkland, P.: Soft Systems Methodology. In: Rosenhead, J. (ed.) Rational Analysis for a Problematic World. John Wiley and Sons, Chichester (1989)
4. Checkland, P.B.: Soft systems methodology. A thirty year retrospective. In: Checkland, P.B., Scholes, J. (eds.) Soft Systems Methodology in Action. Wiley, Chichester (1999)
5. Cole, R.A., Mariani, J., Uszkoreit, H., Zaenen, A., Zue, V. (eds.): Survey of the State of the Art in Human Language Technology (1996),
http://cslu.cse.ogi.edu/HLTsurvey/HLTsurvey.html