VERNON'S COLLECTORS GUIDE TO ORDERS, MEDALS & DECORATIONS - 3rd edition, by Sydney B Vernon  see Medal Links

DIE EHRENZEICHEN DES DEUTCHEN REICHES - by Von Hessenthal & Schreiber

DEUTCHE ORDEN UND EHRENZEICHEN BIS 1945 - by J�rg Nimmergut
(I only have volume II, anyone help in getting the other volumes?)

A HISTORY OF THE EARLY ORDERS OF KNIGHTHOOD AND CHIVALRY - by D. G. Neville