Connolly, Thomas M., and Carolyn E. Beg. 2015. Database Systems: A Practical Approach to Design, Implementation, and Management. Sixth edition. Harlow, Essex, England: Pearson. https://ebookcentral.proquest.com/lib/uea/detail.action?docID=5136720.
Lans, Rick F. van der. 2006. Introduction to SQL: Mastering the Relational Database Language. 4th ed. Upper Saddle River, N.J.: Addison-Wesley. https://www.oreilly.com/library/view/introduction-to-sql/0321305965/?ar.