Lamarque, J. -F., Kiehl, J. T., Shields, C. A., Boville, B. A., & Kinnison, D. (2006). Modeling the response to changes in tropospheric methane concentration: Application to the Permian-Triassic boundary. Paleooceanography, 21, PA3006. doi:10.1029/2006PA001276