For your search you can use the Booleans and, or and not. Without these Booleans a search with and will be performed.
You can also use question marks to match only the beginnings of words - you cannot put question marks at the front or inside of words.

To search in the categories Classification, Language and Country you have to enter the respective abbreviations. There is a list of all used Keywords available.
There is also a list of all used Acronyms and Abbreviations available.