https://knowledge.wharton.upenn.edu/article/deep-work-the-secret-to-achieving-peak-productivity/

Also – https://www.nytimes.com/2019/03/28/smarter-living/productivity-isnt-about-time-management-its-about-attention-management.html?utm_source=hackernewsletter&utm_medium=email&utm_term=fav

People think productivity is caused by time management. It is not. It is caused by attention management. Attention management is decreasing the number of unique tasks per unit time.