@book{Connolly_Beg_2015, address={Harlow, Essex, England}, edition={Sixth edition}, title={Database systems: a practical approach to design, implementation, and management}, url={https://ebookcentral.proquest.com/lib/uea/detail.action?docID=5136720}, publisher={Pearson}, author={Connolly, Thomas M. and Beg, Carolyn E.}, year={2015} }
@book{Lans_2006, address={Upper Saddle River, N.J.}, edition={4th ed}, title={Introduction to SQL: mastering the relational database language}, url={https://www.oreilly.com/library/view/introduction-to-sql/0321305965/?ar}, publisher={Addison-Wesley}, author={Lans, Rick F. van der}, year={2006} }