It all comes together here at the Central Library of the Brooklyn Library. If you can't get it here, you need to go to the New York Branch. But chances are, they have it here.
First, the building. It's worth the trip just to see the architecture. The building is impressive and the main lobby does offer exhibits from time to time.
But the helpful staff and the deep selection of books, that is why people come from all over to visit. Two huge floors open to the public, not including the reading room of books that you can only reference and the "special order" books available to read in the library.
If you need it, you can get it here. Or they will order it for you. Great staff, by the way, and well worth the trip for that book you really need.