1. Lecture Notes in Computer Science;H Yun,2019
2. Lecture Notes in Computer Science;M Sheng,2020
3. World Wide Web Consortium, et al.: RDF 1.1 concepts and abstract syntax (2014)
4. Thompson, H.S., Mendelsohn, N., Beech, D., Maloney, M.: W3C xml schema definition language (xsd) 1.1 part 1: Structures. The World Wide Web Consortium (W3C), W3C Working Draft, December 3 (2009)
5. Wusteman, J.: Document type definition (DTD). Marcia J. Bates, 1640–1647 (2010)