the difference between england the uk great britian and the british isles. Ah finally!!! An explanation!
Euler diagram - Wikipedia, the free encyclopedia
Venn diagrams morphing into Euler circles.
Euler and Venn Diagrams: They Aren’t Just for Fun
Euler Diagrams Overview
Euler diagrams . . . see for their use in diagramming syllogisms and for info on Venn diagrams.
Euler Diagram - online puzzle