--- a/Paper/document/root.bib	Thu Mar 18 23:39:48 2010 +0100
+++ b/Paper/document/root.bib	Fri Mar 19 09:40:34 2010 +0100
@@ -1,3 +1,13 @@
+@incollection{UrbanNipkow09,
+  author = {C.~Urban and T.~Nipkow},
+  title = {{N}ominal {V}erification of {A}lgorithm {W}},
+  booktitle={From Semantics to Computer Science. Essays in Honour of Gilles Kahn},
+  editor={G.~Huet and J.-J.~L{\'e}vy and G.~Plotkin},
+  publisher={Cambridge University Press},
+  pages={363--382},
+  year=2009
+}
+
 @InProceedings{Homeier05,
   author = 	 {P.~Homeier},
   title = 	 {{A} {D}esign {S}tructure for {H}igher {O}rder {Q}uotients},