Most books are available in three formats: PDF, paperback, or hardback. See descriptions regarding particular titles. I have made the PDF versions available with somanauts abroad especially in mind, as prohibitive postal costs prevent me from shipping books overseas.
The Integral Anatomy Series was originally published as a set of 4 DVDs, before I decided to make it available to view for free online. A very limited supply of physical DVD sets still exist for those who have no internet connection, or are just into collecting old-school physical media! I have no plans to reprint on plastic ever again ;)
Course Bundles for online courses save you money. Because your courses never expire, you can purchase the discounted bundle, then complete them for your certificates over time as credits are needed. Smart!