Expert Search is a kind of powerful and specific searching, include Boolean operators.

Search Pattern >> Type in words or phrases in Search Pattern box.
Field/Category >> Select Field/Category Ex. Author, Title, Subject, etc. 
Database >> Select Database.
Search >> Click Search for searching.
Reset >> Click Reset for clear words or phrases in new search.
Steps in Using Boolean/Expert Search
And ELIB system will search for records containing both words in the same or different field.
Or ELIB system will search for records containing either the first word or the second word or both, in the same or different field.
Not ELIB system will search for records containing the first word and not the second word.
Adjacent ELIB system will search for records which have both words next to each other in the same field 
With ELIB system will search for records containing both words in the same field.