Machine Learning with Symbolic Methods and Knowledge Graphs:co-located with European Conference on Machine Learning and Principles and Practice of Knowledge Discovery in Databases (ECML PKDD 2021) : Virtual, September 17, 2021 - Alam, M.; Ali, M.; Groth, P.; Hitzler, P.; Lehmann, J.; Paulheim, H.; Rettinger, A.; Sack, H.; Sadeghi, A.; Tresp, V. (Alam, M, Ali, M, Groth, P, Hitzler, P, Lehmann, J, Paulheim, H, Rettinger, A, Sack, H, Sadeghi, A & Tresp, V (eds) 2021, Machine Learning with Symbolic Methods and Knowledge Graphs : co-located with European Conference on Machine Learning and Principles and Practice of Knowledge Discovery in Databases (ECML PKDD 2021) : Virtual, September 17, 2021. CEUR Workshop Proceedings, vol. 2997, Aachen. < http://ceur-ws.org/Vol-2997 >, 2021)