Observational constraints on cosmological future singularities Jose Beltrán Jiménez, Ruth Lazkoz, Diego Sáez-Gómez and Vincenzo Salzano Eur. Phys. J. C, 76 11 (2016) 631 Published online: 19 November 2016 DOI: 10.1140/epjc/s10052-016-4470-5