At the bottom of the advanced search page you will find your search history. It lists all the searches, of any type, you have made in this session on the database. You can use this menu to combine searches.
The new combined search will then show up in the Search History list. Click on the number in the results column to see the records that match your search.
Tip: If you want to use multiple operators, combine them in steps. For instance you could combine two searches with OR and then combine the result and another search with AND.
The advanced search option lets you combine multiple elements using field tags and Boolean Operators. The field tag codes are displayed on the right of the search page. It also provides a Search History list, which is like a menu of preformed searches from which you can combine previous searches.
When you enter your search, it will show up in the Search History and show you how many results there are. Click that number to see the results that meet those search criteria.
You could use the field tags for Topic (TS), Title (TI) and Year Published (PY) to search for articles about NASA's space missions in a specific year. Use boolean operators to connect the terms.
TS=space AND TI=NASA AND PY=1969
*A full list of field tags can be found on the advanced search screen.