Liber quadratorum

The Liber quadratorum was a mathematical text written in the 13th century by Fibonacci. It enabled the solving of diophantine equations of the second degree.
The Eighth Doctor stopped the Sulumian Thorgan from killing Fibonacci before the Italian had written the Liber quadratorum. (PROSE: )
Category:Mathematics from the real world
Category:Non-fiction books
Category:Books from the real world