APA

Allen B., . (1999). images of the world:photography at the national geographic. washington: national geographic society.

Chicago

Allen B.Thomas, . 1999. images of the world:photography at the national geographic. washington: national geographic society.

Harvard

Allen B., . (1999). images of the world:photography at the national geographic. washington: national geographic society.

MLA

Allen B.Thomas, . images of the world:photography at the national geographic. washington: national geographic society. 1999.