Multi-qubit stabilizer and cluster entanglement witnesses M. A. Jafarizadeh, G. Najarbashi, Y. Akbari and H. Habibian Eur. Phys. J. D, 47 2 (2008) 233-255 Published online: 29 February 2008 DOI: 10.1140/epjd/e2008-00028-0