Are You Getting the Right Amount of Sleep?
https://www.walgreens.com/health/womens-health/a/Are-You-Getting-the-Right-Amount-of-Sleep/1330

How Much Sleep Do You Need?
https://chriskresser.com/how-much-sleep-do-you-need/

Physical Side Effects of Oversleeping
https://www.webmd.com/sleep-disorders/guide/physical-side-effects-oversleeping#1

The myth of the eight-hour sleep
https://www.bbc.com/news/magazine-16964783