Pfiffner, J. P. (2004). The character factor: How we judge America's presidents. Texas A & M University Press.
Dyfyniad Arddull ChicagoPfiffner, James P. The Character Factor: How We Judge America's Presidents. College Station, Tex.: Texas A & M University Press, 2004.
Dyfyniad MLAPfiffner, James P. The Character Factor: How We Judge America's Presidents. Texas A & M University Press, 2004.
Rhybudd: Mae'n bosib nad yw'r dyfyniadau hyn bob amser yn 100% cywir.