Books can be attributed to "Unknown" when the author or editor (as applicable) is not known and cannot be discovered. If at all possible, list at least one actual author or editor for a book instead of using "Unknown".
Books whose authorship is purposefully withheld should be attributed instead to Anonymous.
I really liked it because it confirmed something I've been thinking about for a while now: work less and live more. Use your time to be with your loved ones and enjoy your hobbies. Spend less time being angry and more time building community.