Cesare Pautasso JOpera: An Agile Environment for Web Service Composition with Visual Unit Testing and Refactoring. 311-313 2005 conf/vl/2005 VL/HCC http://doi.ieeecomputersociety.org/10.1109/VLHCC.2005.48 db/conf/vl/vlhcc2005.html#Pautasso05