Collaboration Technologies and Social Computing : 27th International Conference, CollabTech 2021, Virtual event, August 31 - September 3, 2021, Proceedings / by CollabTech (Conference) (27th : 2021 : Online), organiser 642947, Hernández-Leo, Davinia, editor 642948, Hishiyama, Reiko, editor 642949, Zurita, Gustavo, editor 642950, Weyers, Benjamin, editor 642951, Nolte, Alexander, editor 642952, Ogata, Hiroaki, editor 609841