@unpublished{FischerShaki2015,
  author    = {Fischer, Martin H. and Shaki, Samuel},
  title     = {Two steps to space for numbers},
  series = {Frontiers in psychology},
  volume    = {6},
  journal   = {Frontiers in psychology},
  publisher = {Frontiers Research Foundation},
  address   = {Lausanne},
  issn      = {1664-1078},
  doi       = {10.3389/fpsyg.2015.00612},
  pages     = {3},
  year      = {2015},
  language  = {en}
}
@unpublished{ShakiFischer2015,
  author    = {Shaki, Samuel and Fischer, Martin H.},
  title     = {Newborn chicks need no number tricks. Commentary: Number-space mapping in the newborn chick resembles humans' mental number line},
  series = {Frontiers in human neuroscienc},
  volume    = {9},
  journal   = {Frontiers in human neuroscienc},
  publisher = {Frontiers Research Foundation},
  address   = {Lausanne},
  issn      = {1662-5161},
  doi       = {10.3389/fnhum.2015.00451},
  pages     = {3},
  year      = {2015},
  language  = {en}
}
@unpublished{FischerSixtusGoebel2015,
  author    = {Fischer, Martin H. and Sixtus, Elena and G{\"o}bel, Silke M.},
  title     = {Commentary: A pointer about grasping numbers},
  series = {Frontiers in psychology},
  volume    = {6},
  journal   = {Frontiers in psychology},
  publisher = {Frontiers Research Foundation},
  address   = {Lausanne},
  doi       = {10.3389/fpsyg.2015.00227},
  pages     = {3},
  year      = {2015},
  language  = {en}
}