@article{Schmidt2011,
  author    = {Hans-J{\"u}rgen Schmidt},
  title     = {Gauss-Bonnet lagrangian G lnG and cosmological exact solutions},
  journal   = {Physical review : D, Particles, fields, gravitation, and cosmology},
  volume    = {83},
  number    = {8},
  doi       = {10.1103/PhysRevD.83.083513},
  year      = {2011},
}