deletions | additions       diff --git a/bibliography/biblio.bib b/bibliography/biblio.bib  index b31b19c..e3fb4d0 100644  --- a/bibliography/biblio.bib  +++ b/bibliography/biblio.bib 
...
}  @book{2007, @book{weske2007,  doi = {10.1007/978-3-540-73522-9},  url = {http://dx.doi.org/10.1007/978-3-540-73522-9},  year = {2007},