Fogel, Robert William. <br/><br/>
Time on the cross / 
by Robert William Fogel and Stanley L. Engerman. 
 - London :  Wildwood House,  [1974] 
<br/><br/>Bibliography: Supp. v. p. 249-267. 
<br/><br/>Primary v. The economics of American Negro slavery -- Supplement v. Evidence and methods. 
<br/><br/><label>Subjects--Topical Terms: </label><br/>Slave labor -- United States.--Slave labor -- United States.<br/>Afro-Americans -- Economic conditions.--Afro-Americans -- Economic conditions.<br/>Slavery -- United States -- Economic aspects.--Slavery -- United States -- Economic aspects.--Slavery -- United States -- Economic aspects.