If you go to one of the usual online booksellers (like Amazon or Barnes&Noble) and search for “Apache Modules”, you’ll get two results, both of which are expected if you know the subject. You might get an extra result or two from general Apache books that mention modules.
Out of interest, I just tried the same search at Waterstones, one of the most likely UK high street booksellers to have such books on the shelf. And there I got not two but four results. The other two are titles I am also aware of, but which were both long-since abandoned by their authors and/or publishers.
These books never existed, beyond their ISBNs and optimistic publicity. Yet you can buy them online, in exactly the same way you buy a real book! Entering the ISBNs at Amazon, I can buy them there too, though at least an innocent search there doesn’t lead me to them.
What happens to your order for such a phantom book?