Search for litterture at Lund University Libraries (LUB) through the library catalogue Lovisa. If you want to get hold of a book that is at another library at Lund University you can make a request for it and ask to pick it up at the Library of Mathematics (choose Matematiska biblioteket as pick up location).
Libris is the national library catalogue where you can search for literture at university libraries and other speciliezed libraries in Sweden. If you want a book that is not at the Lund University Library, then you can request it through inter library loan.
Card index catalogue
There are some literature that you can't find through Lovisa or Libris, since it has not been catalogued yet. If the book was published before 2001, then a way to find it is to use one of the card index catalogues in the library. The card index for books on Statistics and probability is by the copy machine. The card index for other books are by the library disk.