Crawford, A. (2010). Yorkist lord: John Howard, Duke of Norfolk, c.1425-1485. Continuum.
Cita Chicago (17th ed.)Crawford, Anne. Yorkist Lord: John Howard, Duke of Norfolk, C.1425-1485. London: Continuum, 2010.
Cita MLA (9th ed.)Crawford, Anne. Yorkist Lord: John Howard, Duke of Norfolk, C.1425-1485. Continuum, 2010.
Atenció: Aquestes cites poden no estar 100% correctes.