@ARTICLE{AmokraneTCC13, 
author={Amokrane, Ahmed and Zhani, Mohamed Faten and  Langar, Rami and Boutaba, Raouf and  Pujolle, Guy}, 
 journal={TRANSACTIONS ON CLOUD COMPUTING, IEEE},
 title={Greenhead: Virtual Data Center Embedding Across Distributed Infrastructures}, 
year={2013}, 
volume={1}, 
number={1}, 
pages={36-49}, 
}