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About query

Type words describing the subject of you query in input field of search form and press 'Enter' key or click 'Search' button.

Common (stop) words exclusion

Common words, such as 'the', 'where', etc, are ignored because they are not useful to discriminate documents and didn't improve search quality. If you insist to not ignore them, use plus sign '+' before the word, for example, '+the'. Any punctuation marks are ignored.

Words exclusion

Use minus sign '-' before word to exclude documents containing that word. For example, to find information about Paris but exclude pages with companies offering place in a tourist group, one may use query 'paris -group'.

Search for several words using 'and', 'or'

Search results on default includes only those pages which contain all words from query. If you wish to search documents for any words from your query you have to use vertical sign '|' between words. Operation any has higher priority than operation and, so query 'lections mathematics|physics' will find lections on mathematics and physics, but not lections on mathematics and any documents about physics.

Phrase search

Use double quotes to search for phrases (order of words is important), for example: "lectures on astrophysics". Phrase search could be combined in query with other search terms using 'and', 'any' operators: query "lectures on astrophysics" | "handbook on astronomy" will find documents with phrases "lectures on astrophysics" or "handbook on astronomy". Words in phrase are not expanded and used as is, also stop-words are not ignored. It's possible to exclude documents with certain phrase using prefix "-" (see words exclusion).


Our search system automatically takes into account various forms of words in english and russian languages. For example, queries 'lecture', 'lectures' are equivalent. If you want to search for exact form of some word from your query use exclamation sign '!' before that word, for example, query 'search !system'. Select 'Exact search' checkbox in search form to not automatically expand query.


Search is case insensitive, i.e. queries 'lecture', 'LeCTure' are identical.

Handling misprints (spell checking)

If your query produces too little results, our spell checking software tries to find most close words, based on words similarity and statistics. For example, if you misprint query 'supenvae stars', then our engine will generates alternative spelling 'supernovae stars', which produces more relevant search results.

Grouping search results

Search results are grouped by site, so it's easy to see most relevant documents from different sites. To see all results from selected site use link 'Show all results'.

Similar documents

Documents similarity is estimated using the number of most often common words (HTML tags are ignored) in documents.

Site Search

To restrict search to a specific site click on it's name on Sites page.

Cached link

Click cached link to display web page as it looked at the moment when crawler got it. It might be useful in case the original page is unavailable. Query terms are highlighted.

Documents formats

Search engine recognizes plain text, HTML, pdf, Microsoft doc, ps formats.