diff --git a/gipp.bib b/gipp.bib
index ff3083a11f220888def67ca2805c8ec3957e3f4c..4588e60937bfdb63aa5567322006db3ca2f412b8 100644
--- a/gipp.bib
+++ b/gipp.bib
@@ -1144,13 +1144,14 @@
   author    = {Cohl, Howard S. and Greiner{-}Petter, Andr{\'{e}} and Schubotz, Moritz},
   editor    = {Rabe, Florian and Farmer, William M. and Passmore, Grant O. and Youssef, Abdou},
   publisher = {Springer},
-  url       = {https://doi.org/10.1007/978-3-319-96812-4\_4},
-  biburl    = {https://citation-needed.springer.com/v2/references/10.1007/978-3-319-96812-4_4?format=bibtex&flavour=citation},
+  url       = {https://doi.org/10.1007/978-3-319-96812-4_4},
+  biburl    = {https://dblp.uni-trier.de/rec/bibtex/conf/mkm/CohlGS18},
   booktitle = {Intelligent Computer Mathematics - 11th International Conference, {CICM} 2018, Hagenberg, Austria, August 13-17, 2018, Proceedings},
   date      = {2018},
   doi       = {10.1007/978-3-319-96812-4_4},
   keywords  = {schubotzCV},
   pages     = {39--52},
+  preprint  = {http://hcohl.sdf.org/CICM2018_Chap4.pdf},
   series    = {Lecture Notes in Computer Science},
   title     = {Automated Symbolic and Numerical Testing of {DLMF} Formulae Using Computer Algebra Systems},
   volume    = {11006},