Primo includes everything that is in the WU Catalog plus more online resources and image databases. You can easily limit your results by format, author, etc.
Use the WU Catalog when you know the title or author of an item. The Classic Catalog is also good for browsing subject headings, authors, and titles; and searching by ISBN or call number.
MOBIUS is a consortium of academic libraries in Missouri. The COOL thing about MOBIUS is that you can transfer your search to the MOBIUS Catalog in one click from the WU Catalogs. MOBIUS requests are filled within 3-7 days. You'll be emailed once the item is available.
WorldCat identifies what items libraries worldwide (mainly US) hold. There are two interfaces WorldCat (FirstSearch) and WorldCat.org. Once you find your item, use the ILLiad link to request the item via Interlibrary Loan. You'll be emailed when the item is available