@article{amultilevelcollaborativefilteringmethod,
  title = {A multi-level collaborative filtering method that improves recommendations},
  author = {Polatidis Nikolaos and Georgiadis Christos K.},
  year = {2018},
  eprint = {1804.08891},
  archivePrefix = {arXiv},
  url = {http://arxiv.org/abs/1804.08891v1},
}