Power nap - https://www.nytimes.com/2017/06/23/smarter-living/take-naps-at-work-apologize-to-no-one.html

How to take nap - http://cn.wsj.com/big5/20171024/LIF172127.asp?source=rss

Pulling an All-Nighter? This Is the Ideal Nap Strategy to Beat Fatigue, Analysis Finds - https://nicenews.com/health-and-wellness/ideal-nap-strategy-after-pulling-all-nighter/

Take a nap is good! - http://cn.wsj.com/big5/20130917/ATG133550.asp

Pulling an All-Nighter? This Is the Ideal Nap Strategy to Beat Fatigue, Analysis Finds - https://nicenews.com/health-and-wellness/ideal-nap-strategy-after-pulling-all-nighter/