Remove redundant info from bib-file

references.bib

@@ -43,6 +43,6 @@
   Booktitle	= {{FME} 2003: Formal Methods},
   Volume	= 2805,
   Pages		= {855--874},
-  Publisher	= {Springer Berlin Heidelberg},
+  Publisher	= {Springer},
   Address	= {Berlin, Heidelberg}
 )