--- a/thys/Paper/document/root.bib	Tue Mar 08 09:25:17 2016 +0000
+++ b/thys/Paper/document/root.bib	Tue Mar 08 10:21:18 2016 +0000
@@ -20,6 +20,16 @@
   series =    {LNCS}
 }
 
+@book{Pierce2015,
+  author = {B.~C.~Pierce and C.~Casinghino and M.~Gaboardi and
+            M.~Greenberg and C.~Hri\c{t}cu and 
+            V.~Sjoberg and B.~Yorgey},
+  title = {{S}oftware {F}oundations},
+  year = {2015},
+  publisher = {Electronic textbook},
+  note = {\url{http://www.cis.upenn.edu/~bcpierce/sf}}
+}
+
 @Misc{Kuklewicz,
   author = 	 {C.~Kuklewicz},
   title = 	 {{R}egex {P}osix},