Database System Concepts, Abraham Silberschatz, Henry F. Korth, S. Sudarshan, 2020 (McGraw-Hill Education) - A foundational textbook offering comprehensive coverage of database principles, including detailed explanations and examples of SQL.
PostgreSQL 16 Documentation: Chapter 4. SQL Syntax, The PostgreSQL Global Development Group, 2025 - Official documentation providing an authoritative reference for SQL syntax and commands, relevant for understanding standard SQL.
SQLZoo SQL Tutorial, SQLZoo, 2024 - An interactive online platform offering practical exercises to practice and learn SQL queries from basic to advanced levels.