pages={226--231},
year={2009},
organization={IEEE}
-}
\ No newline at end of file
+}
+
+@incollection{ref232,
+ title={A review on localization in wireless sensor networks},
+ author={Kuriakose, Jeril and Joshi, Sandeep and Raju, R Vikram and Kilaru, Aravind},
+ booktitle={Advances in signal processing and intelligent recognition systems},
+ pages={599--610},
+ year={2014},
+ publisher={Springer}
+}
+
+@article{ref233,
+ title={Localization techniques in wireless sensor networks},
+ author={Alrajeh, Nabil Ali and Bashir, Maryam and Shams, Bilal},
+ journal={International Journal of Distributed Sensor Networks},
+ volume={2013},
+ year={2013},
+ publisher={Hindawi Publishing Corporation}
+}
