Cornerstone Computer Science Publications Relational Databases Paper in which Edgar Codd state the relational database principles: CODD, E. F. A Relational Model of Data for Large Shared Data Banks. Information Retrieval.Volume 13. Number 6. June 1970. Communications of the ACM. pp. 377-387. doi:10.1145/362384.362685 Cost-based optimizer for searching and retriving data from a relational database: SELINGER, P. G., ASTRAHAN M. M., CHAMBERLIN, D. D., LORIE, R. A., PRICE. T. G., Access Path Selection in a Relational Database Management System. SIGMOD '79: Proceedings of the 1979 ACM SIGMOD international conference on Management of data. https://doi.org/10.1145/582095.582099 SQL - Structure Query Language CHAMBERLIN, D. D., BOYCE, R. F. 1974. SEQUEL: A structured English query language. In Proceedings of the 1974 ACM SIGFIDET (now SIGMOD) workshop on Data description, access and control (SIGFIDET '74). Association for Computing Machinery, New York, NY, USA, 249–264. https://doi.org/10.1145/800296.811515 CHAMBERLIN, D. D. Early History of SQL. IEEE Annals of the History of Computing. Volume: 34, Issue: 4, Oct.-Dec. 2012. https://doi.org/10.1109/MAHC.2012.61 Metadata GRIFFEL, D., MCINTOSH, S. Administrative Data Methods For Information Naming Systems (ADMINS) - A Progress Report. Center for International Studies Massachusetts Institute of Technology. 1967. https://dspace.mit.edu/bitstream/handle/1721.1/82974/09487802.pdf?sequence=1