Nowadays, it's not difficult to get books in foreign languages. You can buy books in an online bookshop.
Although, if you are in Barcelona (Spain), there are some bookshops that offer books in English and, also, learning material.
Here's a list of bookshops in Barcelona. If you know more bookshops with foreign languages books in Barcelona or in another city, you can leave a comment.
Hibernian BooksSecond hand books in English and a small selection of new books. You can find a few ones in other languages such as Italian or German.
C. Montseny 17
+34 93 2174796
http://www.hibernian-books.comBCN Books bookshopFocus on learning material, although, it's got other books in English. Three shops:
C. Roger de Llúria, 118
C. Amigó, 81
C. Riera d'Horta, 32
+34 93 4763343
http://www.bcnbooks.comLibreria Anglesa Come InLearning material plus a good range of other sort of books in English.
C. Balmes, 129 bis
+34 93 453 12 04 / +34 93 453 18 06
http://www.libreriainglesa.comAlibri LlibreriaIt's got some foreign languages learning material: English, French, German or Russian.
C. Balmes, 26
+34 93 3170578
http://www.alibri.esFnac BarcelonaBooks in English and learning material.
Plaza Catalunya, 4
+34 93 3441800
http://www.fnac.esLinks