TY - JOUR T1 - A solid state 13C NMR study of kerogen degradation during black shale weathering JF - Geochim. Cosmochim. Acta Y1 - 2001 A1 - Petsch, S. T. A1 - Smernik, R. J. A1 - Eglinton, T. I. A1 - Oades, J. M. VL - 65 N1 - id: 277 ER -