Spontaneous flow in polar active fluids: the effect of a phenomenological self propulsion-like term Francesco Bonelli, Giuseppe Gonnella, Adriano Tiribocchi and Davide Marenduzzo Eur. Phys. J. E, 39 1 (2016) 1 Published online: 14 January 2016 DOI: 10.1140/epje/i2016-16001-2