@article{williamsgray2007-17535834,
  author  = {Williams-Gray, C. H. and Foltynie, T. and Brayne, C. E. and Robbins, T. W. and Barker, R. A.},
  title   = {{Evolution of cognitive dysfunction in an incident Parkinson's disease cohort}},
  journal = {Brain : a journal of neurology},
  year    = {2007},
  doi     = {10.1093/brain/awm111},
  pmid    = {17535834},
  url     = {https://doi.org/10.1093/brain/awm111}
}