Book of Readings on the Eucharist by 
Redemptive encounter: the Precious Blood in the spirituality of Maria de Mattias by 
New Catholic Encyclopedia by 
Catechism of the Catholic Church by 
The Last Secret of Fatima by Searching the catalog and databases for Catholic subjects using keywords can be effective. If you want to narrow down the search and really focus on items that are subject specific, using subject heading searches can help.
Subject headings sometimes seem logical and sometimes they don't. One advantage of identifying the language used for a subject heading is discovering the term that is used to describe something across all the different library resources. Relying on keywords can leave your results open to a little interpretation or guesswork.
Here are some different examples of subject headings that might change what results you get when searching.
General topics:
Places:
People/Dieties:
Titles:
