The default search is "free-text". Click on Search Form to bring it up:
The Search Form allows you to use the free text search without having to enter the Boolean operators (AND, OR, NOT):
- All of these words: The results will include all of the words entered (replaces AND).
- At least one of these words: The results will include one or more of the words entered (replaces OR).
- None of these words: The results will exclude all of those words.
- This exact phrase: The results will bring the exact string of character (replaces quotation marks "..."). For example, entering the words water pollution will yield articles containing this exact phrase.