Did you know that you can borrow books and documents from other universities?
If you would like to borrow a book at another university in Quebec, you can do so by using your McGill ID. Then, you will be able. You can find more information on this page.
If you need something that the library doesn't have, you can also put in an inter-library loan request, which means that another university in the world will send it to you. Be mindful that this can take a few weeks. For more information, consult this page.