Παραπομπή APA

Urwick, L. (1957). Leadership in the twentieth century. Sir Isaac pitman.

Παραπομπή Chicago Style

Urwick, L.F. Leadership in the Twentieth Century. London: Sir Isaac pitman, 1957.

Παραπομπή MLA

Urwick, L.F. Leadership in the Twentieth Century. Sir Isaac pitman, 1957.