Updateing Readme to give proper reference

README.md

@@ -8,6 +8,27 @@ or use our free and daily updated online service at
 
 http://map.project-osrm.org
 
+## References in publications
+
+When using the code in a (scientific) publication, please cite
+
+@inproceedings{luxen-vetter-2011,
+ author = {Luxen, Dennis and Vetter, Christian},
+ title = {Real-time routing with OpenStreetMap data},
+ booktitle = {Proceedings of the 19th ACM SIGSPATIAL International Conference on Advances in Geographic Information Systems},
+ series = {GIS '11},
+ year = {2011},
+ isbn = {978-1-4503-1031-4},
+ location = {Chicago, Illinois},
+ pages = {513--516},
+ numpages = {4},
+ url = {http://doi.acm.org/10.1145/2093973.2094062},
+ doi = {10.1145/2093973.2094062},
+ acmid = {2094062},
+ publisher = {ACM},
+ address = {New York, NY, USA},
+}
+
 ## Current build status
 
 | build config |  branch | status |