First-order formalism for twinlike models with several real scalar fields D. Bazeia, A. S. Lobão, L. Losano and R. Menezes Eur. Phys. J. C, 74 2 (2014) 2755 Published online: 12 February 2014 DOI: 10.1140/epjc/s10052-014-2755-0