ISBN   0810938405   Pfeiffer, Heinrich (2007) (in German). Die Sixtinische Kapelle neu entdeckt . Stuttgart: Belser. ISBN   9780810938403 .   Stone, Irving (2004). The Agony and the Ecstasy . London: Nal Trade. ISBN   0451213238 . http://en.wikipedia.org/wiki/The_Agony_and_the_Ecstasy_%28novel%29 .   . Previously publish by Doubleday in 1961. Blech, Benjamin ; Doliner, Roy (2008). The