Add reference to README

Author: hackermd

README.md

@@ -90,6 +90,28 @@ Currently, the viewer only supports
 * brightfield illumination (no fluorescence)
 * 2D images (no z-stacks)
 
+## Citation
+
+Please cite the following article when using the viewer for scientific studies: [Herrmann et al. J Path Inform. 2018](http://www.jpathinformatics.org/article.asp?issn=2153-3539;year=2018;volume=9;issue=1;spage=37;epage=37;aulast=Herrmann):
+
+```None
+@article{jpathinform-2018-9-37,
+    Author={
+        Herrmann, M. D. and Clunie, D. A. and Fedorov A. and Doyle, S. W. and Pieper, S. and
+        Klepeis, V. and Le, L. P. and Mutter, G. L. and Milstone, D. S. and Schultz, T. J. and
+        Kikinis, R. and Kotecha, G. K. and Hwang, D. H. and Andriole, K, P. and Iafrate, A. J. and
+        Brink, J. A. and Boland, G. W. and Dreyer, K. J. and Michalski, M. and
+        Golden, J. A. and Louis, D. N. and Lennerz, J. K.
+    },
+    Title={Implementing the {DICOM} standard for digital pathology},
+    Journal={J Path Inform},
+    Year={2018},
+    Volume={9},
+    Number={37}
+}
+
+```
+
 ## Support
 
 The developers gratefully acknowledge their reseach support: