Get Better Sleep - How to Maximize your Sleep to Feel More Rested in Less Time

Sleep Smarter by  Sean Stevenson
https://sleepsmarterbook.com/

Jim Kwik 
https://kwikbrain.com/reading?utm_source=Google&utm_medium=Search+Ads&utm_campaign=Reading+Offer&gclid=CjwKCAjw7eSZBhB8EiwA60kCW9alwk-bpyj5I0qsCF61TgR5YEd1zWpkwnSQGpTPEXQQPZdKEbVSqRoC4acQAvD_BwE 

https://www.prospectivedoctor.com/mcat-mnemonics-stages-of-sleep-and-brain-waves/