References/Notes/Attributions:
Source
M. Friendly (2000), Visualizing Categorical Data: http://euclid.psych.yorku.ca/ftp/sas/vcd/catdata/vision.sas
References
M. G. Kendall & A. Stuart (1961), The Advanced Theory of Statistics, Vol. 2. Griffin, London.
M. Friendly (2000), Visualizing Categorical Data. SAS Institute, Cary, NC.