Command language
Command language gives you features to search exactly what you are looking for in one search.

Here are some of the commands:

• and - both words are in the records: "hillary" and "clinton"
  
• or - one of the words (or both) are in the records:"sri lanka" or "ceylon"
  
• not - one specific word is not in the records: "obama" not "michelle"
• truncation - you want variations of a word (no quotes): japan* and politic*
• masking - you are in doubt of one character in a word - mask one character ?: wom?n
• parenthesis - you want to combine more words: (walk* or trek*) and "nepal"
• put your words in quotes unless they are truncated - as shown in examples. If you want to search words that are operators (and or not) just type them - no quotes: eg. but not for me - taxing the rich or the poor. Not/or/and will not be seen as an operator but just a word.
• if you want to use command language in other fields than freetext: use paranthesis to indicate command language. E.g. in title: (color or colour)

Search codes
Refine your search by using search codes:

• author: fo
• isbn and issn: is
• lix: ix
• publisher: fl
• series: se
• subject: em
• title: ti
• year: år

Examples:
fo="irving" and ti="twisted"
em=clima* and em=change* and år=2015
ti="house of cards" and "spacey"