Database System Concepts, Avi Silberschatz, Henry F. Korth, S. Sudarshan, 2019 (McGraw-Hill) - A foundational textbook covering the theoretical aspects of database systems, including the relational model, data types, and integrity constraints.
Chapter 8. Data Types, PostgreSQL Global Development Group, 2024 - Official documentation for PostgreSQL, providing detailed explanations and examples of various data types, their storage characteristics, and usage.