Die Zentralstelle Deutscher Genalogie-Mappenstuecke
When I was stymied with my research in Germany I came across an entry in the old Microfiche Catalog, in the Author-Title section. The Leipzig Archive in Saxony was listed as an author under: Die Zentralstelle Deutscher Genalogie. There were many entries listed, but one was particulary interesting: Mappenstuecke. These were assorted family records on many microfilms. They are not listed alphabetically, so you have to check column after column. I happened to come across "The Stuelers from Muehlhausen. I ordered the film, bingo, 500 years of one of my lines. And that led to many more. Why did I not find them on the computer? The computer only listed a summary of the family records, and it did not list the Stuelers. I have not tried to duplicate the search today with what is available on the web. This was 15 years ago. I was born in Germany and speak German, which helps.