AU is part of Washington ResearchLibrary Consortium, so if you can't find what you're looking for you can borrow from other local colleges and universities.
Although the 2nd floor is deemed "silent", the 3rd floor is a great place for intense studying with virtually any noise--try sitting at one of the tables facing SIS!
The entire second floor is one massive QUIETstudy space, with chairs and outlets, and lots of quiet. We encourage civitas here – be mindful of the needs of the students around you.