From the first article you mention, "Subject to the qualifications already expressed, there is a certain consistency in that there is a definite, but not necessarily linear, decrease in productivity for each additional 10 hours per week."
Your first link merely cites my link, and provides no data of it's own. Your second link is from 1913 and provides little data. Your third link is blogspam for my link.
The nasa article is interesting, and hints that maybe long hours can increase error rates (which would be very bad if you are highly risk averse). It draws no conclusions.
The microsoft article is irrelevant. Your last link has no data.
Apparently it takes more than 5 minutes of google to find something that addresses these questions. And not a single link you provided even attempts to answer the question of whether some individuals can productively work 60 hour weeks. Every single study with data addresses the average person.
The nasa article is interesting, and hints that maybe long hours can increase error rates (which would be very bad if you are highly risk averse). It draws no conclusions.
The microsoft article is irrelevant. Your last link has no data.
Apparently it takes more than 5 minutes of google to find something that addresses these questions. And not a single link you provided even attempts to answer the question of whether some individuals can productively work 60 hour weeks. Every single study with data addresses the average person.