The Library does not ordinarily purchase textbooks.
If your required reading is not a textbook, it is possible you will find it in the library's collections. Search by title or author in Scholar OneSearch, limiting your search to "Library Catalogs." The Browse search allows for the most precise searching by title or author.
Also, check to see if your book is on Reserve. Search Scholar OneSearch, limiting your search to "Course Reserves" using the drop down menu.