1. Beyer, K. et al.: On synopses for distinct-value estimation under multiset operations. In: Proceedings 2007 ACM SIGMOD, Beijing, China, pp. 199–210 (2007)
2. Brickley, D., Guha, R.V. (eds.): RDF Schema 1.1. W3C Recommendation, 25 February 2014
3. Cyganiak, R., Wood, D., Lanthaler, M. (eds.): RDF 1.1 Concepts and Abstract Syntax. W3C Recommendation, 25 February 2014
4. Lecture Notes in Computer Science;JSA Eichler,2017
5. García, G.M., Izquierdo, Y.T., Menendez, E., Dartayre, F., Casanova, M.A.: RDF keyword-based query technology meets a real-world dataset. In: Proceedings of 20th International Conference on Extending Database Technology, Venice, Italy (2017)