Island: An interlinked semantically-enriched blockchain data framework - Kalafatelis, Alexandros; Konstantinos Panagos; Anastasios E. Giannopoulos; Sotirios T. Spantideas; Nikolaos C. Kapsalis; Marios Touloupou; Evgenia Kapassa; Leonidas Katelaris; Panayiotis Christodoulou; Klitos Christodoulou; others (Economics of Grids, Clouds, Systems, and Services: 18th International Conference, GECON 2021, Virtual Event, September 21–23, 2021, Proceedings 18, 2021)