^Andrea Palladio, The Four Books on Architecture, translated by Robert Tavernor and Richard Schofield (Cambridge, Massachusetts: MIT Press, 2002) bk. 2, ISBN0-262-66133-0.
^Douglas Lewis, "Freemasonic Imagery in a Venetian Fresco Cycle," in Hermeticism and the Renaissance, edited by Ingrid Merkel and Allen G. Debus(Washington, D. C.: Folger Shakespeare Library, 1988), p. 366, ISBN0-918016-85-1.
^Wittkower, Architectural Principles in the Age of Humanism (London: Tiranti) 1962:72.