Peterson, R. (1997). Pigskin: The early years of pro football. Oxford University Press.
Cita Chicago Style (17a ed.)Peterson, Robert. Pigskin: The Early Years of Pro Football. New York: Oxford University Press, 1997.
Cita MLA (9a ed.)Peterson, Robert. Pigskin: The Early Years of Pro Football. Oxford University Press, 1997.
Precaución: Estas citas no son 100% exactas.