NavList:

Yes. Closed. I would not be surprised if a well-known boutique publisher of astronomical resources picks up their product line, and I would bet that negotiations are underway as we speak.

I guess you missed my post on 28 Dec 2020 about another book by Meeus:

"... This is just the sort of thing you'll enjoy if you're a NavList sort with a particular interest in the astronomy side of the subject. And I thought to myself, "Oh I haven't looked at this in years. I'll just crack open the cover and have a look at the table of contents". And in "Mathematical Astronomy Morsels III" I see that article number 52 is entitled "More Sunshine near the Polar Circles". Well, of course! I'm attaching a quick photo of [...]

Now you want your very own copies of these "Morsels", don't you? They were formerly published by a little company called Willmann-Bell. The owners have recently retired, and the business is closed. You're too late! No morsels for you!! There are a few copies of the original "Morsels" (Morsels I) on abebooks and ebay, at relatively high prices. There are no copies of "Morsels III" on abebooks.com or on ebay. There are two copies listed on amazon.com both with an asking price of $668.93 ...which is not a real price."

I haven't looked for the various volumes of Morsels, but Astronomical Algorithms by Jean Meeus is available as a pdf from multiple online sources, and the code is out there, too. I'm not sure where they stand legally, but they (the pdfs at least) are easily located by a standard search.

Frank Reed