Kerr, G. (2009). Leaders who changed the world. Futura.
Dyfyniad Arddull ChicagoKerr, Gordon. Leaders Who Changed the World. London: Futura, 2009.
Dyfyniad MLAKerr, Gordon. Leaders Who Changed the World. Futura, 2009.
Rhybudd: Mae'n bosib nad yw'r dyfyniadau hyn bob amser yn 100% cywir.