@article{DBLP:journals/ipl/GoldmannGH94,
  author    = {Mikael Goldmann and
               Per Grape and
               Johan H{\aa}stad},
  title     = {On Average Time Hierarchies},
  journal   = {Inf. Process. Lett.},
  volume    = {49},
  number    = {1},
  year      = {1994},
  pages     = {15-20},
  ee        = {http://dx.doi.org/10.1016/0020-0190(94)90048-5},
  bibsource = {DBLP, http://dblp.uni-trier.de}
}