@article{VernerHerrmannTrocheetal.2013,
  author    = {Martin Verner and Martin J. Herrmann and Stefan J. Troche and Claudia M. Roebers and Thomas H. Rammsayer},
  title     = {Cortical oxygen consumption in mental arithmetic as a function of task difficulty: a near-infrared spectroscopy approach},
  journal   = {Frontiers in Human Neuroscience},
  volume    = {7},
  number    = {217},
  doi       = {10.3389/fnhum.2013.00217},
  year      = {2013},
}