add additional reference for 8div* instances

Sascha_Kurz2/sub.bib

+@incollection{ubt_eref40887,
+          author = {Daniel Heinlein and Thomas Honold and Michael Kiermaier and Sascha Kurz and Alfred Wassermann},
+       booktitle = {The Tenth International Workshop on Coding and Cryptography 2017 : WCC Proceedings},
+         address = {Saint-Petersburg},
+           month = {September},
+           title = {Projective divisible binary codes},
+            year = {2017},
+             url = {https://eref.uni-bayreuth.de/40887/},
+        keywords = {divisible codes; projective codes; partial spreads}
+}
+
 @article{heinlein2017classifying,
   title   =  {Classifying optimal binary subspace codes of length 8, constant dimension 4 and minimum distance 6},
   author  =  {Heinlein, Daniel and Honold, Thomas and Kiermaier, Michael and Kurz, Sascha and Wassermann, Alfred},
   journal =  {Designs, Codes and Cryptography},
   note    =  {arXiv preprint arXiv:1711.06624},
   year    =  {to appear},
-  doi     =  {10.1007/s10623-018-0544-8},
+  doi     =  {10.1007/s10623-018-0544-8}
 }
\ No newline at end of file