Building analytical three-field cosmological models J. R. L. Santos, P. H. R. S. Moraes, D. A. Ferreira and D. C. Vilar Neta Eur. Phys. J. C, 78 2 (2018) 169 Published online: 26 February 2018 DOI: 10.1140/epjc/s10052-018-5614-6