@Article{ajp10-muelleta,
  author = {Müller, T. and Weiskopf, D.},
  title  = {{Distortion of the stellar sky by a Schwarzschild black hole}},
  year   = {2010},
  pages  = {204-214},
  journal = {{American Journal of Physics}},
  volume = {{78}},
  doi = {{10.1119/1.3258282}}
}