https://www.sleepfoundation.org/circadian-rhythm
Slideshow Photos
A walk through the stages of sleep | Sleeping with Science, a TED series Video
https://www.thensf.org/what-is-rem-sleep/
Circadian Rhythm Picture https://www.healthline.com/health/healthy-sleep/stages-of-sleep

Dream sources

https://www.wondriumdaily.com/why-do-we-dream/ https://pubmed.ncbi.nlm.nih.gov/15766897/
Why do we dream video?

Sleep Disorder Sources

https://www.mayoclinic.org

How to Impove Sleep Sources

Photos https://www.cdc.gov/sleep/about_sleep/sleep_hygiene.html https://www.hopkinsmedicine.org/health/wellness-and-prevention/exercising-for-better-sleep