These books are great resources for those interested in the history of obstetrics and gynecology. To use them, simply open the pages and start reading. You can also use them as reference materials when studying related topics. When handling the books, be gentle as the covers have some wear and tear. To maintain them, store them in a dry and cool place. Avoid exposing them to direct sunlight for long periods as it may cause further discoloration. If there's dust on the pages, you can use a soft brush to gently remove it.