Usually, searches can be limited according to certain characteristics; in many databases you can use the following specifying features:
- Date, specifying since what time or between which dates should the document have been published.
- Full-text, specifying that only full texts are needed.
- Publication/Journal, in case you want to search only within a specific journal.
- Publication type, specifying books, articles, etc.
Basic Search offers less possibilities for limiting your search; Advanced Search offers some more. In databases on some specific field of science you can limit your search according to many specific features.