@article{Fridman2008,
  author    = {Aleksandr A. Fridman},
  title     = {{\"U}ber die Kr{\"u}mmung des Raumes},
  journal   = {Zeitschrift f{\"u}r Physik <Berlin>},
  volume    = {10},
  pages     = {377 -- 386},
  year      = {2008},
}