Panos Constantopoulos Vicky Dritsou Eugénie Foustoucos Developing Query Patterns. 119-124 2009 ECDL http://dx.doi.org/10.1007/978-3-642-04346-8_13 conf/ercimdl/2009 db/conf/ercimdl/ecdl2009.html#ConstantopoulosDF09