Digital Transformation and Global Society 4th International Conference, DTGS 2019, St. Petersburg, Russia, June 19-21, 2019, Revised Selected Papers - Alexandrov, Daniel A.; Alexandrov, Daniel A.; Boukhanovsky, Alexander V.; Boukhanovsky, Alexander V.; Chugunov, Andrei V.; Chugunov, Andrei V.; Kabanov, Yury; Kabanov, Yury; Koltsova, Olessia; Koltsova, Olessia; Musabirov, Ilya; Musabirov, Ilya (Springer International Publishing : Imprint: Springer, 2019)