APA

Christiansen E., Oxford University Press, . (1967). The origins of military power in Spain. London: Oxford University Press.

Chicago

Christiansen E, Oxford University Press, . 1967. The origins of military power in Spain. London: Oxford University Press.

Harvard

Christiansen E., Oxford University Press, . (1967). The origins of military power in Spain. London: Oxford University Press.

MLA

Christiansen E, Oxford University Press, . The origins of military power in Spain. London: Oxford University Press. 1967.