As a shout-out, that’s a good one. Very fine books, thoughtful and morally gentle. “Good” books in more than one sense.
Never heard of these before. Do they have to be read in order?
They are each more or less stand-alone, but there are mild character arcs–for instance, one if the last books is about one if the main characters going into retirement. Looks like you can get them pretty cheap as ebooks in Omnibus editions- 3 or so novels at a time for eight bucks. (Might be some of the dead tree omnibuses for a penny plus shipping, I didn’t check.)
Here is a good article on the series. (I have one or two of those hardback omnibuses–the rest in vintage paperbacks. And all as ebooks from–um–years before official versions were available.)
I have all the omnibus editions and recommend them highly!