Collaborative, trusted and privacy-aware e/m-services: 12th IFIP WG 6.11 conference on e-business, e-services, and e-society, I3E 2013 Athens, Greece, april 25-26, 2013 proceedings Douligeris, C. Polemi, N. Karantjias, A. Lamersdorf, Winfried 2013 - Forschungsinformationssystem der UHH