Low Flying Archive Search - Text Search Hints
It takes a Google-like search string. By default, it will search for any of the terms used but will score articles higher if they contain all the words used, and higher still if they appear as a phrase.
So if I search for "wet sump", the articles containing that phrase will appear first (assuming the sort option is set to relevance rather than date) followed by articles which contain the word "wet" and "sump", followed by documents which contain only one of the words.
You can modify its behaviour as follows:
So the search:
+"wet sump" cavitat* -apolloMeans
find only documents which contain the phrase "wet sump" but do not contain the word "apollo". Score documents higher if they also contain any words like cavitate or cavitation.