Mathematical Writing [pdf]
jmlr.csail.mit.eduThere is another version of this book that includes the illustrations missing from this version, at https://www-cs-faculty.stanford.edu/~knuth/papers/cs1193.pdf or http://i.stanford.edu/pub/cstr/reports/cs/tr/88/1193/CS-TR-8... -- would be good to combine the two (keep the figures/inserts from the scanned version, and the rest from this version).
See also the videos of the lectures of which these are the notes (https://cs.stanford.edu/~knuth/klr.html), at https://www.youtube.com/watch?v=mert0kmZvVM + https://www.youtube.com/playlist?list=PLOdeqCXq1tXihn5KmyB2Y...
Someone should make a webpage which has the list of videos (ideally without relying on YouTube), and next to each of them the corresponding notes chapter.