iRequire: Gathering end-user requirements for new apps. - Norbert Seyff; Gregor Ollmann; Manfred Bortenschlager (RE, 2011)

AppEcho: a user-driven, in situ feedback approach for mobile platforms and applications. - Norbert Seyff; Gregor Ollmann; Manfred Bortenschlager (MOBILESoft, 2014)