First detection of extragalactic 13CO(6-5) line emission G.J. Stacey, S. Hailey-Dunsheath, T. Nikola, T.E. Oberst, S.C. Parshley and C.M. Bradford EAS Publications Series, 31 (2008) 151-154 Published online: 04 October 2008 DOI: 10.1051/eas:0831029