diff --git a/bibliography.bib b/bibliography.bib
index 210d39a..2398e98 100644
--- a/bibliography.bib
+++ b/bibliography.bib
@@ -62,3 +62,12 @@
 	date = {2019-10-28},
 }
 
+@BOOK{berger2023-mz,
+  title     = "Kombinatorik",
+  author    = "Berger, Peter",
+  publisher = "Springer Berlin Heidelberg",
+  year      =  2023,
+  address   = "Berlin, Heidelberg",
+  copyright = "https://www.springernature.com/gp/researchers/text-and-data-mining",
+  language  = "de"
+}