From the Franklin homepage, select the Search by Instructor, Department, Course, & Section under Course Reserves in the middle of the page. The Franklin location for these items will say Temporarily Shelved at Lippincott Library - Reserve Desk. Reserve books can be checked out for three hours for use in the library. See for example Perloff's Microeconomics : theory and applications with calculus which is on reserve for MGEC 611.
Use Franklin, Penn Libraries' Online Catalog. Sample Searches:
If Penn does not own a particular title or if a book that you want is checked out, search the BorrowDirect or E-ZBorrow catalogs. Books requested from one of our partner institutions generally arrive within 3-5 business days.