What are the conventions regarding search strings?

The search engine is diacritics- and case-insensitive.
Wildcards:
'%' (the percent sign) can be used as a wildcard for any number of characters while '_' (underscore) for one character only. Examples:

psycho%

psychologist_

Collocations, sentences:
Several words separated by spaces will be searched for as a collocation (sentence). Example:

psychological experiments

Logical operators:
ACCUM , (comma)
Returns the items containing some of the words entered. The items found are sorted by the number of times the words occur in them.
Using this operator is particularly convenient when you do not know, for instance, the exact name of the publication you are searching for. Example:

Lord, of, Rings
AND & (ampersand)
Returns the items containing all the words entered. The items found are sorted by the number of times the words occur in them.
NEAR ; (semicolon)
Returns the items containing all the words entered. The items found are sorted by the distance between the words.
OR | (vertical bar)
Returns the items containing at least one of the words entered. The items are sorted by the number of times the word(s) occurs in these.
NOT ˜ (tilde)
Returns the items not containing the word entered.
( ) (parentheses)
Use parentheses to search for collocations. Examples:

(labor OR labour) & force

(Carl | Karl) AND Jung

MINUS - (hyphen)
Returns the items containing the word preceding the hyphen and not containing the word following it. For instance, if you enter

sci-fi

the search returns the results that contain sci, but not fi. Hence, if you really want to search for the whole "sci-fi" expression, you should enter

sci\-fi

The same applies to hyphenated names. When searching for a person named Al-Gaf, you should enter

Al\-Gaf
.
Reserved characters:
The following characters and expressions have special search-related meaning:
& | , - ; $ ! ? > * # : % _ ( ) [ ] { } \ @ AND OR ACCUM MINUS EXECUTE EXEC SQE SYN PT RT TT BT NT BTG NTG BTP NTP
Provided you want to make them part of your search string without using their search-specific function, you should enclose them in braces or escape them with a backslash '\'. Examples:

{e-learning}

or

e\-learning

Words that are ignored:
The search engine ignores the following words:
s k v o u a i z ve ze ke se na přes pod nad od také on ona ono oni ony ty já ano ne
University degrees appended to people's names are also ignored.