diff --git a/proseminar.bib b/proseminar.bib
index b6b7e28..b349a57 100644
--- a/proseminar.bib
+++ b/proseminar.bib
@@ -1,18 +1,18 @@
 @book{heuser,
-    author = {Heuser, Harro},
-    title = {Gew{\"o}hnliche Differentialgleichungen},
-    subtitle = {Einf{\"u}hrung in Lehre und Gebrauch},
-    publisher = {Vieweg+Teubner Verlag},
-    year = {2009},
-    edition = {6},
-    pages = {453,460,462},
+    author = "Heuser, Harro",
+    title = "Gew{\"o}hnliche Differentialgleichungen",
+    subtitle = "Einf{\"u}hrung in Lehre und Gebrauch",
+    publisher = "Vieweg+Teubner Verlag",
+    year = "2009",
+    edition = "6",
+    pages = "453,460,462",
 }
 
 @book{grune,
-    author = {Gr{\"u}ne, Lars AND Junge, Oliver},
-    title = {Gew{\"o}hnliche Differentialgleichungen},
-    subtitle = {Eine Einführung aus der Perspektive der dynamischen Systeme},
-    publisher = {Vieweg+Teubner Verlag},
-    year = {2009},
-    pages = {10--16},
+    author = "{Gr{\"u}ne, Lars} and {Junge, Oliver}",
+    title = "Gew{\"o}hnliche Differentialgleichungen",
+    subtitle = "Eine Einführung aus der Perspektive der dynamischen Systeme",
+    publisher = "Vieweg+Teubner Verlag",
+    year = "2009",
+    pages = "10--16",
 }
\ No newline at end of file