Search for Coin Catalog

Hello everyone, I'm looking for the coin catalogue in medieval Europe, can someone recommend me some digital or printed catalogue in Holy Roman Empire? Specifically in Germany.

And could someone tell me what's the meaning of the number and letter in the last third line(Erl.67, Fd Hersbruck 34, Slg.Erl 28)?
 

https://en.numista.com/literature/catalogues.php

Herbert Justin Erlanger; 1979. Die Reichsmünzstätte in Nürnberg . Verein für Geschichte der Stadt Nürnberg, Nürnberg, Bavaria, Germany.

Bank Leu, Munzen & Medaillen (publisher); 1989. Nürnberg: Sammlung Herbert J. Erlanger - Auktion in Zürich. Bank Leu, Munzen & Medaillen, Zürich, Switzerland.

I suspect that sources in auction listing are specific to Nuremberg coins. Search says that first source is in Deutsche Nationalbibliothek. Third one is for sale in online store.

Fd stands for Fund so for the discovery of a treasure.

Fund Hersbruck 1936 book by Gebhardt

Older catalogues are often spezialized to a mint, a region, a ruler etc

one that I like that covers quite a lot is this

https://en.numista.com/literature/volume_group.php?id=13