a) by companies

There are several ways to be more specific in your search query:

"Phrase"

Search an exact match of your query, e.g. "Member lists"

+Phrase

Given word has to be in the result, e.g. +Gestapo

-Phrase

Exclude given word from search, e.g. -Gestapo

Use the following syntax to restrict the search to specific fields:

field:"phrase"

For instance, you can find all descriptions that have the phrase "Auschwitz Birkenau" in their titles by searching for title:"Auschwitz Birkenau".

The following fields are currently available:

• identifier
• title
• creator
• person
• place
• subject
• address