@article{learningfirstorderdefinableconceptsover,
  title = {Learning first-order definable concepts over structures of small degree},
  author = {Martin Grohe and Martin Ritzert},
  year = {2017},
  eprint = {1701.05487},
  archivePrefix = {arXiv},
  url = {http://arxiv.org/abs/1701.05487v1},
}