Dennis L. KappenPejman Mirza-BabaeiLennart E. NackeMotivational Affordances for Older Adults' Physical Activity Technology: An Expert Evaluation.388-4062019HCI (27)https://doi.org/10.1007/978-3-030-22012-9_28conf/hci/2019-27db/conf/hci/hci2019-27.html#KappenMN19