To make your search through OALibrary more comfortable, we allow the use of AND, OR, -, "". Using these terms you can specify your keyword search more precisely.
You can use the word AND between keywords to indicate that you are looking for documents that contain both words in your search. For example, if you search for apple AND pear, only documents that have both the word apple and the word pear will appear. This is the configuration that our search engine uses as default, and therefore you do not really have to write it to use the search engine in this way.
Using the word OR between two words will show documents that have at least one of those words. Using our previous example (apple OR pear), any document having the word apple will appear, independently of whether it has the word pear, and vice versa.
In case you do not want to include documents with a certain word in your search, just add it in the form -apple. In this case, it will prevent the search to show documents with the word apple in it.
Using quotes around a sentence, in order to look for documents that have that exact sentence, is also allowed. For example, you could use "apples are red", and only documents with that exact sentence will be shown.
Lastly, we feel the need to remark that, if you use quotes, the OR parameter cannot be used at the same time, as it will be taken as an AND search. Also, keep in mind that the default configuration is set as an AND search, and therefore there is no need to write it if that is your desired type of search.