In gReader you can search for articles. By pressing on the Search button on the action bar you can enter a query you like to search. The item list will display articles where your query is in the title or the content. It is very easy to find articles.
The query support different kind of input:
All the operators can be combined together in a query.
You can save the query in the filter to have a quick access later. You will find the filter in the tag list view.