Brueghel: Jan Brueghel D. Ä. in Der Alten Pinakothek by Mirjam Neumeister
This textbook is an affordable alternative to the newer edition.
Brueghel: Jan Brueghel d. Ä. in der alten Pinakothek (German Edition), , 9783777
A nice touch in this textbook is the quick start guide for each chapter.