Diane Mary Schweizer and Michael F Goodchild.
Data Quality and Choropleth Maps: An Experiment with the Use of Color.
In Proceedings, GIS/LIS, pp. 686--699, 1992.

Bibtex:

@InProceedings{  schweizer:1992:DQCM,
  author = 	 {Diane Mary Schweizer and Michael F Goodchild},
  title = 	 {Data Quality and Choropleth Maps: An Experiment with the Use of Color},
  booktitle =    {Proceedings, GIS/LIS},
  pages = 	 {686--699},
  year = 	 {1992},
}