TY - JOUR AU - Xie, S. TI - Changes in the global carbon cycle occurred as two episodes during the Permian-Triassic crisis JA - Geology PY - 2007/// VL - 35 SP - 1083 EP - 1086 PB - Nature Publishing Group M3 - 10.1130/G24224A.1 N1 - 10.1130/G24224A.1 UR - http://dx.doi.org/10.1130/G24224A.1 ER -