diff --git a/gipp.bib b/gipp.bib
index f5985f37181d6711b58be6db3c06dd79b0df7f36..cf1093da1b1fe9f831aaa2eb36ea4eb81373de14 100644
--- a/gipp.bib
+++ b/gipp.bib
@@ -1329,7 +1329,6 @@
   publisher = {ACM},
   biburl    = {https://dblp.org/rec/bib/conf/recsys/SchwarzerBSMG17},
   booktitle = {Proceedings of the Eleventh {ACM} Conference on Recommender Systems, RecSys 2017, Como, Italy, August 27-31, 2017},
-  core      = {B},
   date      = {2017},
   doi       = {10.1145/3109859.3109981},
   keywords  = {schubotzCV,preprint},