Petter Bae Brandtzæg Asbjørn Følstad Jan Heim Enjoyment: Lessons from Karasek. 55-65 2005 Funology http://dx.doi.org/10.1007/1-4020-2967-5_6 series/hci/BlytheOMW05 db/series/hci/BlytheOMW05.html#BrandtzaegFH05