@article{EichlerKumarPohl2013,
  author    = {David Eichler and Rahul Kumar and Martin Pohl},
  title     = {Is the galatic cosmic-ray spectrum constant in time?},
  journal   = {The astrophysical journal : an international review of spectroscopy and astronomical physics},
  volume    = {769},
  number    = {2},
  doi       = {10.1088/0004-637X/769/2/138},
  year      = {2013},
}