https://www.themanual.com/culture/why-4-day-work-weeks-are-good-for-everyone/#:~

https://www.themanual.com/culture/why-4-day-work-weeks-are-good-for-everyone/#:~:text=As%20such%2C%20there%20are%20also,a%20more%20efficient%2C%20productive%20workplace
this is research article ^