Update refrence

spec/bib.bib

@@ -261,13 +261,19 @@
 }
 
 @inproceedings{schurr-2021,
-  author = {
-    Hans-Jörg Schurr and Mathias Fleury and Martin Desharnais
-  },
-  title = {Reliable Reconstruction of Fine-Grained Proofs in a Proof Assistant},
-  booktitle = "CADE 2021",
-  year = {2021},
+  author="Schurr, Hans-J{\"o}rg
+    and Fleury, Mathias
+    and Desharnais, Martin",
+  editor="Platzer, Andr{\'e}
+    and Sutcliffe, Geoff",
+  title="Reliable Reconstruction of Fine-grained Proofs in a Proof Assistant",
+  booktitle="CADE 28",
+  year="2021",
+  publisher="Springer International Publishing",
+  address="Cham",
+  pages="450--467",
   series = lncs,
+  doi= {10.1007/978-3-030-79876-5\_26}
 }
 
 @article{de-nivelle-2005,