http://dx.doi.org/10.1103/PhysRevE.87.023305 (Verlagsversion)
http://arxiv.org/abs/1210.7867 (Preprint)
PhysRevE.87.023305.pdf (Verlagsversion), 2MB
Dirks, A., Eckstein, M., Pruschke, T., & Werner, P. (2013). Extracting spectral properties from Keldysh Green functions. Physical Review E, 87(2): 023305. doi:10.1103/PhysRevE.87.023305.