--- a/Paper/document/root.bib	Thu Jan 24 18:59:49 2013 +0100
+++ b/Paper/document/root.bib	Fri Jan 25 15:57:58 2013 +0100
@@ -74,4 +74,25 @@
   number    = {3},
   year      = {1968},
   pages     = {147-148}
-}
\ No newline at end of file
+}
+
+
+
+@Book{Berger66,
+  author = 	 {R.~Berger},
+  title = 	 {{T}he {U}ndecidability of the {D}omino {P}roblem},
+  journal = 	 {Memoirs of the American Mathematical Society},
+  year = 	 {1966}
+}
+
+
+@Article{Robinson71,
+  author = 	 {R.~M.~Robinson},
+  title = 	 {{U}ndecidability and {N}onperiodicity for {T}ilings of the {P}lane},
+  journal = 	 {Inventiones Mathematicae},
+  year = 	 {1971},
+  volume = 	 {12},
+  pages = 	 {177--209}
+}
+
+