Blackmail or war.

MLA

Tabouis, Geneviève. Blackmail Or War. Harmondsworth: Penguin Books, 1938.

APA

Tabouis, G. (1938). Blackmail or war. Harmondsworth: Penguin Books.

Chicago

Tabouis, Geneviève Blackmail Or War. Harmondsworth: Penguin Books, 1938.