You ask them to order it for you from another library. It's called interlibrary loan, and it's free.
But will they allow me to take it home?
You know wrong. The only books you can't take home with you are rare manuscripts and archival copies, and books put on reserve by professors so that they are available for the whole class to use.
Maybe it depends on the library in question?
Here you have this for example:
"The materials brought from other libraries can be used only in the library's reading room for a certain period of time as specified by a library that loaned the material. The cost of bringing the library materials from other libraries is covered by the reader according to postal fees."
Not at any library I heard of. Certainly not in Poland. I ordered hundreds of books that way during my stay in Poland.
Maybe you ordered books from Polish libraries?
Here you have fees for bringing books from abroad in National Library:
That's expensive. It cost me less to buy the books I mentioned in an online store and I could keep them for life...
It's a bit cheaper in the Jagiellonian University:
It's "even" cheaper in Wrocław University, but, still... 50 zł?:
I could buy a book for 50 zł... And I could use it at home whenever I wanted, for as long as I wanted and keep it forever.
For most students, that's a prodigious, or even prohibitive, outlay for mere convenience's sake.
Well, imagine a Polish student would need a book from abroad - he or she would have to pay sth around 50 zł, apparently.
Even after my patient explanation above,
Sorry, Dominic, but it wasn't a "patient" explanation - you behaved like an unpleasant as$hole.
you are still thinking of a library as "books".
No, I'm not. I know you can find more in a library than just books. But that's not what we're discussing right now.