Add missing ref

thesis/references.bib

@@ -21,6 +21,13 @@
   volume = {4}
 }
 
+@article{GeiHal2017,
+  author = {Geiger, R Stuart and Halfaker, Aaron},
+  title = {Operationalizing Conflict and Cooperation between Automated Software Agents in Wikipedia: A Replication and Expansion of “Even Good Bots Fight”},
+  journal = {unpublished},
+  year = {2017}
+}
+
 @inproceedings{GeiRib2011,
   author = {Geiger, R Stuart and Ribes, David},
   title = {Trace Ethnography: Following Coordination through Documentary Practices},