We have chosen to recommend high-quality literature that is still in print. We carry all of the titles, and you can order them individually or save money by ordering a literature package. Many of the titles are also readily available from other online booksellers.
Public libraries in your area may have the titles available. WorldCat is an online database that helps you search the catalogs of multiple libraries in your area if you can't find a book in your local system.
Another amazing resource is Biblioguides. Among the many resources they offer is a list of private lending libraries across the United States (plus a few in Canada and Australia). Many of these were started by homeschooling parents who wanted to share their collections of literature with other families. Some are free while others charge a modest fee to access their collections.