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Essentials of marketing research
Proctor, Tony, (1997)
Kumar, V., (1999)
Prognoseverfahren
Wöller, Rolf, (2008)
“Game on!” Pushing consumer buttons to change sustainable behavior : a gamification field study
Mulcahy, Rory Francis, (2021)
Marketing research : methodological foundations
Churchill, Gilbert A., (2002)
Service branding
Ostrom, Amy L., (2005)