@INPROCEEDINGS {14541,
author={R. Oliveira and Luis M. Borges and F. J. Velez},
doi={0},
booktitle={IEEE International Symp. on Wireless Communication Systems - ISWCS},
title={ A Double Stage Random Access Scheme for Decentralized Single Radio Cognitive Networks},
year={2013},
month={August},
volume={.},
pages={1-5} 
}