Cita APA (7a ed.)

BRUUN, G. The world in the Twentieth century. D. C. Heath And Company.

Cita Chicago Style (17a ed.)

BRUUN, Geoffrey. The World in the Twentieth Century. D. C. Heath And Company.

Cita MLA (8a ed.)

BRUUN, Geoffrey. The World in the Twentieth Century. D. C. Heath And Company.