Still other sources are available in printed form.
Those that have been edited, reprinted in facsimiles, or transferred to microfilm can be borrowed through E Z Borrow or interlibrary loan if they are not in Tripod.
Books printed in the 16th or 17th century are kept in libraries' rare book collections. You can go to Bryn Mawr, the University of Pennsylvania, and other local libraries to see the early science books which they own.
While some primary source books and other kinds of materials have been digitized, there are great numbers which exist only in print or manuscript, particularly when it comes to documents and records which are often in one unique copy. Visiting a rare book library will give you access to additional source material, as you can readily see from the resources on Friends Hospital here in Haverford's Special Collection Library.
Use the databases below to search for primary source material in special collection libraries.