SMC X-3: the closest ultraluminous X-ray source powered by a neutron star with non-dipole magnetic fieldS. S. Tsygankov, V. Doroshenko, A. A. Lutovinov, A. A. Mushtukov and J. PoutanenA&A, 605 (2017) A39DOI: https://doi.org/10.1051/0004-6361/201730553