Sébastien SalvaAn Approach for Testing Web Service Compositions When Internal Messages are Unobservable.334-34520119Int. J. Electron. Bus. Manag.4http://ijebm.ie.nthu.edu.tw/IJEBM_Web/IJEBM_static/Paper-V9_N4/A05.pdfdb/journals/ijebm/ijebm9.html#Salva11