In an 8-Hour Day, the Average Worker Is Productive for 2 Hours and 53 Minutes
September 18, 2017 at 7:22:09 AM GMT+2 * - permalink -

- https://www.inc.com/melanie-curtin/in-an-8-hour-day-the-average-worker-is-productive-for-this-many-hours.html

Why Do We Work Eight Hours a Day? : Discovery News
September 5, 2013 at 4:49:03 PM GMT+2 * - permalink -

- http://news.discovery.com/history/history-of-the-8-hour-work-day-120501.htm#mkcpgn=rssnws1