To carry out a complex or comprehensive search, it is usually best to search for each concept individually and then combine them together using the Advanced Search screen.
- Click on the Search link at the top of the screen, then Advanced Search
- Select the searches you wish to combine, with the appropriate search operator, AND / OR / NOT, and click on Combine
- Run the search
A video walkthrough is available.
You can also use the search numbers to construct the search directly, eg (#1 AND #2) NOT #3. This can be particularly useful if you are using a complex combination and you need to use brackets to make the order clear. Alternatively, you could combine results #1 and #2 to make a new search result #4, and then combine that with search #3.
If you have combined searches, and then you use the history to edit one of the original search queries, this will affect all later combined searches based on it.