• Famous Problems of Geometry and How to Solve Them, by Benjamin Bold, Dover Publications.
     
    The Golden Ratio, the Story of Phi, the World's Most Astonishing Number, by Mario Livio, Broadway Books.
     
    Challenging Problems in Geometry, by Alfred S. Posamentier and Charles T. Salkind, Dover Publications.
     
    The Pythagorean Theorem, A 4,000 - Year History, by Eli Manor, Princeton University Press.