EJB Design Patterns (published March 2002) ISBN 0471208310
Consists of 20 EJB-specific patterns written a style similar to AlexandrianForm. The book is 'lower level' than most patterns books, in that it is intented to cover EJB-specific implementation and design issues.
The book also contains:
A chapter on going from requirements to patterns-driven design
A Chapter on Build-system and Junit testing strategies (contributed by RandyStafford)