@INPROCEEDINGS{coopis11-TA, AUTHOR = {Christos Tryfonopoulos and Laura Maria Andreescu}, TITLE = "{Pricing Information Goods in Distributed Agent-based Information Filtering}", BOOKTITLE = "{Proceedings of the 19th International Conference on Cooperative Information Systems (CoopIS)}", YEAR = {2011}, PAGES = {163--181}, MONTH = {October}, ADDRESS = "{Crete, Greece}", }