The Balfour Library contributes funds to e-books@cambridge every year and more and more of the books on students' reading lists are being purchased on a monthly basis.
The ebooks@cambridge collections comprise hundreds of the books most used by Cambridge students and they are available online 24/7 through Newton, the online library catalogue, at http://www.lib.cam.ac.uk/newton/
There may be many more e-books relevant to you that we don’t have in printed format so for a full list of ALL the e-books available see http://www.sel.cam.ac.uk/ebooks@cambridge/09_05%20All%20titles%20available.pdf and the printouts on the top of the Overnight Loan shelves in the library.