For more accurate results, you can use the following rules.

Match all of the terms: includes all of the terms typed into the search box.

Example: 'alstom power' searches for documents with both the keywords alstom and power.

Match at least one of the terms

Example: 'alstom OR power' searches for documents with EITHER keywords alstom OR power.

Match the exact phrase

Example: "'alstom power'" searches for documents where alstom and power appear together in the document in the order they were entered.

Exclude terms from the search

Example: 'power -station' searches for documents where the term power appears but not station.