Three-forms in supergravity and flux compactifications Fotis Farakos, Stefano Lanza, Luca Martucci and Dmitri Sorokin Eur. Phys. J. C, 77 9 (2017) 602 Published online: 12 September 2017 DOI: 10.1140/epjc/s10052-017-5185-y