APA

Fogel R. W. &. S. L. E., .Time on the Cross:: Economics of American Negro Slavery. : Little, Brown and Company.

Chicago

Fogel Robert William & Stanley L Engerman, .Time on the Cross:: Economics of American Negro Slavery. : Little, Brown and Company.

Harvard

Fogel R. W. &. S. L. E., .Time on the Cross:: Economics of American Negro Slavery. : Little, Brown and Company.

MLA

Fogel Robert William & Stanley L Engerman, .: Little, Brown and Company. .