You can buy Study Skills 1-4 (Effective Notetaking, Mnemonics for Study, How to Learn: The 10 principles of effective practice and revision, and Successful Learning Simplified) all together and save. This is only available in digital formats, of course. And only available from my own store, the Kobo store, and the Google store. It is not available in Amazon, and is not likely to ever be, due to the price caps Amazon insists on. However, you can buy it in the Kindle format from my own store.