If a book is not available at the USD Libraries you have two options:
Request your book from the Circuit (the combined catalog for USD, SDSU, UCSD, CSU San Marcos and San Diego County Public Libraries). If you find the book you need in the Circuit you can simply make an online request and have the book delivered to Copley Library.
If a book is not available through the Circuit, or if USD does not have access to a particular article, you can make an interlibrary loan request. To make a request, simply log in with your USD One username and password. The library's Interlibrary Loan Department will borrow your book from participating libraries worldwide.