Reference Topics 9-3

This site investigates the four-color problem:

A beautiful gallery of fractal designs are found on these sites:

A site showing some of Escher’s tessellations is interesting:

This site shows the colorful answer to Problems 24 and 25:… See the whole entry

Reference Topics 9-1

An historical reference, along with a solution and interesting links for the Konigsberg bridge problem is found at this site:

This site provides a thorough overview of the Traveling Salesperson Problem (TSP):

This site, by Chris Caldwell provides … See the whole entry