There was also a pointer to Jeremy C Reed's
http://www.bsdnewsletter.com/2013/12/Features186.html
as well as his book on BSD history
http://www.reedmedia.net/books/bsd-history/ (which I'd love to get a copy
of).
It wasn't clear if it had been published or not from the link
It is still listed in "upcoming books" in the right column of
http://www.reedmedia.net/books/ and is still not completed AFAIK.
Miod