No Library has print or full text copies of everything for immediate access.  If a CU student needs a specific book, article, etc. that the CU Libraries do not own (or have immediate online access to), the student may use Interlibrary loan to request that a copy of a book, article, etc. be sent from a library that does own the item.   Articles are usually sent electronically while books lent by other libraries must be checked out and returned at your home campus Library. Interlibrary Loan can also be used for materials other than books and articles, although they are the most common. For more info, check out the Library's Interlibrary Loan page.