Update README.md

Author: shepnerd

README.md

@@ -10,4 +10,15 @@ This is code for fast visual object counting via example-based density estimatio
  organization={IEEE}
 }
 
-When you use the code, please cite the above paper.
+@article{wang2018manifold,
+ title={Manifold-based visual object counting},
+ author={Wang, Yi and Zou, Yuexian and Wang, Wenwu},
+ journal={IEEE Transactions on Image Processing},
+ volume={27},
+ number={7},
+ pages={3248--3263},
+ year={2018},
+ publisher={IEEE}
+}
+
+When you use the code, please cite the above papers.