Usable error message presentation in the World Wide Web: Do not show errors right away. - Javier A. Bargas-Avila; Glenn Oberholzer; Peter Schmutz; Marco de Vito; Klaus Opwis (Interact. Comput., 2007)

ZeGo: Development and Validation of a Short Questionnaire to Measure User Satisfaction with e-Government Portals. - Javier A. Bargas-Avila; Sébastien Orsini; Marco de Vito; Klaus Opwis (Adv. Hum. Comput. Interact., 2010)