url(r'^lektury/', 'book_list', name='book_list'),
url(r'^lektura/(?P<slug>[a-zA-Z0-9-]+)/polki/', 'book_sets', name='book_shelves'),
url(r'^polki/nowa/$', 'new_set', name='new_set'),
url(r'^lektury/', 'book_list', name='book_list'),
url(r'^lektura/(?P<slug>[a-zA-Z0-9-]+)/polki/', 'book_sets', name='book_shelves'),
url(r'^polki/nowa/$', 'new_set', name='new_set'),