Witold Abramowicz Business Information Systems, 12th International Conference, BIS 2009, Poznan, Poland, April 27-29, 2009. Proceedings http://dx.doi.org/10.1007/978-3-642-01190-0 978-3-642-01189-4 BIS 21 2009 Lecture Notes in Business Information Processing Springer db/conf/bis/bis2009.html