@Book{BioASQ:2016,
  editor    = {Ioannis A. Kakadiaris  and  George Paliouras  and  Anastasia Krithara},
  title     = {Proceedings of the Fourth BioASQ workshop},
  month     = {August},
  year      = {2016},
  address   = {Berlin, Germany},
  publisher = {Association for Computational Linguistics},
  url       = {http://anthology.aclweb.org/W16-31}
}