Aesthetics
Envisioning Information by Edward R. Tufte 1990
http://www.amazon.com/exec/obidos/ASIN/0961392118/qid=950810214/sr=1-7/103-8963442-0381430
The Visual Display of Quantitative Information by Edward R. Tufte
1992
http://www.amazon.com/exec/obidos/ASIN/096139210X/qid=950810214/sr=1-5/103-8963442-0381430
Visual Explanations : Images and Quantities, Evidence and Narrative
by Edward R. Tufte 1997
http://www.amazon.com/exec/obidos/ASIN/0961392126/qid=950810214/sr=1-6/103-8963442-0381430