PG 1018−047: the longest period subdwarf B binary. - Deca, J.; Marsh, T. R.; Østensen, R. H.; Morales-Rueda, L.; Copperwheat, C. M.; Wade, R. A.; Stark, M. A.; Maxted, P. F. L.; Nelemans, G.; Heber, U. (Monthly Notices of the Royal Astronomical Society, 2012)