Stephen Hawing turns up in 'They Saved Lisa's Brain' to help stop Springfield's mass idiocy problem.
The Simpsons: The Complete Tenth Season DVD (2007) Matt Groening cert 12 4
The Simpsons: The Complete Ninth Season DVD (2007) Matt Groening cert 12 4
The Simpsons: The Complete Sixth Season DVD (2005) Matt Groening cert 12 4
The Simpsons: The Complete Seventh Season DVD (2006) Matt Groening cert 12 4
