Macroscopic Greenberg-Horne-Zeilinger state and W state in charge qubits based on Coulomb blockade L. M. Liang and X. B. Wang Eur. Phys. J. D, 57 1 (2010) 141-144 Published online: 26 January 2010 DOI: 10.1140/epjd/e2010-00015-x