Karoline Busse Sabrina Amft Daniel Hecker Emanuel von Zezschwitz "Get a Free Item Pack with Every Activation!". 217-236 2019 18 i-com 3 https://doi.org/10.1515/icom-2019-0012 https://www.wikidata.org/entity/Q126356511 db/journals/icom/icom18.html#BusseAHZ19