Very lucky to find two other great books on German passport regulations from 1936 & 1960. Such books are as valuable as collectibles itself and are a great sources to understand better what we collect. The 1936 book is called “Merkblatt über Passwesen und Passnachschau”. The book was only for official use, so a ordinary citizen couldn’t buy it. It describes the whole processing from application to issuing and to verify a passport and it’s entries. The second book is actually from East Germany (GDR) about customs regulations and inspection but has also a chapter about passports. A nice and rare finding as well.