Fogel, Robert William. <br/><br/>
Time on the cross :  evidence and methods, a supplement / 
by Robert William Fogel and Stanley L. Engerman. 
 - 1st ed. 
 - Boston :  Little, Brown,  c1974. 
 - xi, 267 p. :  ill. ;  22 cm. 
<br/><br/>Includes bibliography. 
<br/><br/><label>LCCN: </label>
<br/><br/><label>Subjects--Topical Terms: </label><br/>Slavery--Economic aspects--United States.