Cita APA (7a ed.)

Fogel, R. W., & Engerman, S. L. (1989). Time on the cross: The economics of American Negro slavery. W.W. Norton.

Cita Chicago Style (17a ed.)

Fogel, Robert William, y Stanley L. Engerman. Time on the Cross: The Economics of American Negro Slavery. New York: W.W. Norton, 1989.

Cita MLA (8a ed.)

Fogel, Robert William, y Stanley L. Engerman. Time on the Cross: The Economics of American Negro Slavery. W.W. Norton, 1989.