You can use the Boolean Operators AND, OR, and NOT within search fields. By default, an AND relationship is assumed between search terms unless another operator is specified.
Boolean operators should be capitalised. If not capitalised they are parsed as search terms and not as Boolean operators.
For more hints and tips why not take a look at our user guides here. For even more details on how to use Boolean operators when searching our main databases CAB Abstracts and Global Health, you can consult the help file here.