Positional uncertainty in manually digitized map data

@article{Bolstad1990PositionalUI,
  title={Positional uncertainty in manually digitized map data},
  author={Paul V. Bolstad and Paul E. Gessler and Thomas M. Lillesand},
  journal={International Journal of Geographical Information Science},
  year={1990},
  volume={4},
  pages={399-412}
}