diff --git a/gipp.bib b/gipp.bib
index 3cac653c7e0c74e168a7bb9e74846d979bfbb1c6..d0d8e94124025cba0aea25739bea61e8c8c28496 100644
--- a/gipp.bib
+++ b/gipp.bib
@@ -1652,6 +1652,7 @@
   date         = {2019},
   issn         = {1027-488X},
   journaltitle = {{European Mathematical Society Newsletter}},
+  keywords     = {preprint,SchubotzCV},
   pages        = {50--52},
   title        = {{Four decades of TeX at zbMATH.}},
   volume       = {112},
@@ -1669,5 +1670,15 @@
   title     = {Forms of Plagiarism in Digital Mathematical Libraries},
 }
 
+@inproceedings{Wortner2019,
+  author    = {Wortner, Patrick and Schubotz, Moritz and Leible, Stephan and Gipp, Bela},
+  location  = {Urbana-Champaign, IL, USA},
+  booktitle = {Proceedings of the workshop on Web Archiving and Digital Libraries (WADL) held in conjunction with the ACM/IEEE Joint Conference on Digital Libraries (JCDL)},
+  date      = {2019-06},
+  keywords  = {preprint,SchubotzCV},
+  preprint  = {https://www.gipp.com/wp-content/papercite-data/pdf/wortner2019.pdf},
+  title     = {Securing the Integrity of Time Series Data in Open Science Projects using Blockchain-based Trusted Timestamping},
+}
+
 @comment{jabref-meta: databaseType:biblatex;
 }