Search tips for KARLA

Searching in the KARLA catalogue portal is similar to using a search engine. The hit lists are sorted by relevance. The following tips may help to optimize your search results.


  • Ranking: Search terms found in the Author and/or Title categories have greater relevance than those found in the publisher or contents categories.
    If search terms appear more than once, this also boosts their ranking. Recent titles are ranked higher than older ones.
    When entering a single search term, the matching one-word titles rank highest in the hit list.
  • Filters: You can narrow your hit list by using various filters (format, subject, author, year of publication).
  • Search operators: If you enter four or more search terms, you will also get hits not matching all terms you used. To modify this, you can use the AND operator or the + sign.
  • Typing errors: Books & more allows minor typing errors and includes variant word forms.
  • Ranking: Search terms found in the keywords or the descriptors of subject databases have greater relevance than those found in keywords supplied by the author, in abstracts or full texts. If search terms appear more than once, this also boosts their ranking. Recent titles are ranked higher than older ones.
    Exact title matches are also ranked very high.
  • Filters: You can narrow your hit list by using various filters. The most important are: source type, subject, publisher, content provider. By using the linkedfull text search limiter you will only get documents with access to licensed full texts and to some open access documents.
  • Search operators: By default all search terms will be combined with AND, but other Boolean operators or proximity operators are also possible.
  • Typing errors: Articles & more allows no typing errors.
  • For one character: Use the question mark ?.
    Example: if you want to search for text or test, enter Te?t.
  • For several characters: Use the asterisk *.
    Example: if you want to search for test, tests or tester, enter Test*.
    This also works within a word: T*ler (finds: taller, tailer, teller, etc.).
  • If you want to search for an exact sequence of words, please use quotation marks.             Example: "Grapes of wrath"
  • The phrase search also helps when searching for specific authors. By entering “surname, first name”, you only search for this one person. Example: “darwin, charles”.
  • Boolean operators allow to combine search terms.
  • The following operators are possible: AND, OR, NOT and in Books & more+ and - too.
  • Boolean operators must be written in capital letters.


  • The AND combination is applied automatically when using up to three search terms. In order to get results matching four or more search terms you will have to combine them actively with AND.
  • Example: you are searching for titles where the words international politics and Ulrich Albrecht occur: international AND politics AND ulrich AND albrecht

+ (only in Books & more)

  • By placing the + operator in front of a word, you also obtain hits where this word is found.
  • Example: +international +politics +ulrich +albrecht


  • Using the OR combination you get hits where one or both words are found.
  • Example: you are looking for titles where the terms alcoholism or drug abuse are found: alcoholism OR drug abuse


  • By placing NOT in front of a word, you exclude the hits that contain this word.
  • Example: you want to search for titles that contain the word economics, but not the word Keynes: economics NOT Keynes
  • NOT has to be used with at least two words. For example, the following search will not provide any hits: NOT economics

- (only in Books & more)

  • If the operator - is placed in front of a word, all the hits that contain this word are excluded.
  • Example: economics -Keynes
  • If you want to execute a subject search combining various operators, please note that there is an order of precedence:
    1. NOT
    2. AND
    3. OR
  • By placing brackets, you can ensure that the search request is performed in the form that you wish. Wildcards or the phrase search can also be used here.
  • For example: you are searching for literature about witch-hunt in the Middle Ages or the early modern times. Your search should look like this: witch-hunt AND (“middle ages” OR “early modern times”)
  • Or if you are looking for literature about diagnosing and treating ligament injuries, for example, but want to exclude the documents that deal with dogs, enter: (ligament*AND diagnos* AND treat*) NOT dog
  • In Articles & more, beside Boolean operators, you can also use proximity operators to establish the maximum distance between your search terms. This option is particularly helpful if you want to search within full texts (see further below).
  • The N (=NEAR) operator searches for the terms in any sequence, the W (=WITHIN) operator in the sequence that you have set.
  • Example 1: football N5 team (finds hits where the two terms are no more than 5 words apart  and in any sequence).
  • Example 2: football W5 team (finds hits where the two terms are no more than 5 words apart and in the set sequence)
  • Proximity operators can be combined with Boolean operators and used for complex search requests.
  • Example: (handball OR football OR basketball) N5 (team OR players)
  • In Articles & more the standard search only browses through the title metadata (author, title, keywords, etc.). However, the full texts of articles, book chapters, e-books, etc. are also indexed.
  • If you want to broaden your search to those full texts, please check the Also search within the  full text option in the Search Expanders.
  • We recommend that you use proximity operators to get results of higher relevance.

By using special search keys, it is possible to display the newly acquired items on a particular subject within a set period. The two keys to use are:
a_date_last_23:[NOW-XDAYS TO NOW] where X is the number of previous days


shelfmark_word_23:"shelf*" where shelf is the beginning of the shelfmark; if 25 pol is used for shelf, for example, only the acquisitions at Holländischer Platz are displayed on the subject of politics. 55 inf would provide new acquisitions in computer science at the site Wilhelmshöher Allee.

a_date_last_23:[NOW-21DAYS TO NOW] AND shelfmark_word_23:"25 pol*"

provides the new acquisitions on the subject of politics within the last 21 days, if it is copied into the KARLA search field.

You can find all about site identifiers (“Wo steht was? = Where are items located?”) and subject groups at Shelfmarks.