- Wed Yourself to UML with the Power of Associations
- Wed Yourself to UML with the Power of Associations, Part 2
- UML Overview by by Mandar Chitnis, Pravin Tiwari, Lakshmi Ananthamurthy
- The Diagrams of UML 2.0 by Scott W. Ambler
- UML 2.1.2 Superstructure Specification