+}
+
+@book{ref222,
+ author = {S. Misra and I. Woungang and S. C. Misra},
+ title = {Guide to Wireless Sensor Networks},
+ publisher = {Springer-Verlag London Limited},
+ year = {2009},
+}
+
+
+@article{ref223,
+ title={Wireless sensor networks: applications and challenges of ubiquitous sensing},
+ author={Puccinelli, Daniele and Haenggi, Martin},
+ journal={Circuits and Systems Magazine, IEEE},
+ volume={5},
+ number={3},
+ pages={19--31},
+ year={2005},
+ publisher={IEEE}
+}
+
+@inproceedings{ref224,
+ title={Probabilistic coverage in wireless sensor networks},
+ author={Ahmed, Nadeem and Kanhere, Salil S and Jha, Sanjay},
+ booktitle={Local Computer Networks, 2005. 30th Anniversary. The IEEE Conference on},
+ pages={8--pp},
+ year={2005},
+ organization={IEEE}
+}
+
+@inproceedings{ref225,
+ title={Incremental Model for Complete Area Coverage in Wireless Sensor Networks},
+ author={Sethi, Hemendra Kumar and Dash, Sasmita and Lenka, Manas Ranjan and Swain, Amulya Ratna},
+ booktitle={Computational Intelligence and Networks (CINE), 2015 International Conference on},
+ pages={92--97},
+ year={2015},
+ organization={IEEE}
+}
+
+@article{ref226,
+ title={Extending the Network Lifetime of Wireless Sensor Networks Using Residual Energy Extraction—Hybrid Scheduling Algorithm},
+ author={CHITRA, M},
+ journal={Int'l J. of Communications, Network and System Sciences},
+ volume={2010},
+ year={2010},
+ publisher={Scientific Research Publishing}
+}
+
+@article{ref227,
+ author = {Mihaela Cardei and
+ David MacCallum and
+ Maggie Xiaoyan Cheng and
+ Manki Min and
+ Xiaohua Jia and
+ Deying Li and
+ Ding-Zhu Du},
+ title = {Wireless Sensor Networks with Energy Efficient Organization},
+ journal = {Journal of Interconnection Networks},
+ volume = {3},
+ number = {3-4},
+ year = {2002},
+ pages = {213-229},
+}
+
+@inproceedings{ref228,
+ author = {D. Zorbas and D. Glynos and P. Kotzanikolaou and C. Douligeris},
+ title = {B\{GOP\}: an adaptive coverage algorithm for wireless sensor networks},
+ booktitle = {Proceedings of the 13th European Wireless Conference},
+ series = {EW'07},
+ year = {2007},
+ location = {Paris, France},
+
+}
+
+@inproceedings{ref229,
+ title={A near optimal algorithm for lifetime optimization in wireless sensor networks},
+ author={Deschinkel, Karine and Hakem, Mourad},
+ booktitle={SENSORNETS 2013, 2nd Int. Conf. on Sensor Networks},
+ pages={197--202},
+ year={2013}
+}
+
+@article{ref230,
+ title={Maximizing system lifetime in wireless sensor networks},
+ author={Alfieri, Arianna and Bianco, Andrea and Brandimarte, Paolo and Chiasserini, Carla-Fabiana},
+ journal={European Journal of Operational Research},
+ volume={181},
+ number={1},
+ pages={390--402},
+ year={2007},
+ publisher={Elsevier}
+}
+
+@inproceedings{ref231,
+ title={Maximize lifetime of heterogeneous wireless sensor networks with joint coverage and connectivity requirement},
+ author={Gu, Yu and Ji, Yusheng and Zhao, Baohua},
+ booktitle={Scalable Computing and Communications; Eighth International Conference on Embedded Computing, 2009. SCALCOM-EMBEDDEDCOM'09. International Conference on},
+ pages={226--231},
+ year={2009},
+ organization={IEEE}
+}
+
+@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}
+}
+
+@inproceedings{ref234,
+ title={UREA: Uncovered region exploration algorithm for reorganization of mobile sensor nodes to maximize coverage},
+ author={Nene, Manisha J and Deodhar, Rajendra S and Patnaik, Lalit M},
+ booktitle={Distributed Computing in Sensor Systems Workshops (DCOSSW), 2010 6th IEEE International Conference on},
+ pages={1--6},
+ year={2010},
+ organization={IEEE}
+}
+
+@inproceedings{ref235,
+ title={Mobility improves coverage of sensor networks},
+ author={Liu, Benyuan and Brass, Peter and Dousse, Olivier and Nain, Philippe and Towsley, Don},
+ booktitle={Proceedings of the 6th ACM international symposium on Mobile ad hoc networking and computing},
+ pages={300--308},
+ year={2005},
+ organization={ACM}
+}
+
+@article{ref236,
+ title={Localization and coverage for high density sensor networks},
+ author={Bahi, Jacques M and Makhoul, Abdallah and Mostefaoui, Ahmed},
+ journal={Computer Communications},
+ volume={31},
+ number={4},
+ pages={770--781},
+ year={2008},
+ publisher={Elsevier}
+}
+
+@article{ref237,
+ title={Hilbert mobile beacon for localisation and coverage in sensor networks},
+ author={Bahi, Jacques M and Makhoul, Abdallah and Mostefaoui, Ahmed},
+ journal={International Journal of Systems Science},
+ volume={39},
+ number={11},
+ pages={1081--1094},
+ year={2008},
+ publisher={Taylor \& Francis}
+}