Extra neutral gauge boson from two versions of the 3-3-1 model in future linear colliders E. Ramirez-Barreto, Y.A. Coutinho and J. Sá Borges Eur. Phys. J. C, 50 4 (2007) 909-917 Published online: 15 March 2007 DOI: 10.1140/epjc/s10052-007-0254-2